- •1496 Corba - Object-Oriented Technology)
- •1432 Five Object Oriented Development Methods, Research report, hp Laboratories,
- •1866 Corba Implementation Descriptions: Object-Oriented Technologies dome
- •135 Based approaches (e.G. Smalltalk handles) allow powerful dynamic typing, as
- •83 There are many definitions of an object, such as found in [Booch 91, p77]:
- •83 There are many definitions of an object, such as found in [Booch 91, p77]:
- •48 Languages that are historically procedural languages, but have been extended with some oo features. Examples: Visual Basic (derived from basic), Fortran 2003, Perl, cobol 2002, php, abap.
- •121 Interface - e.G. Gui
- •197 Sharing and often instances will simply delegate to parents to access methods
- •670 Polymorphic languages can be statically typed to provide strong type checking,
- •Inclusion
- •209 Usage is atypical] See [Booch 94, pp 154-155] for a brief discussion of
- •203 Parents (as any other member) can be added or changed dynamically, providing
- •23 Subtype polymorphism
- •18 A survey by Deborah j. Armstrong of nearly 40 years of computing literature identified a number of "quarks", or fundamental concepts, found in the strong majority of definitions of oop.
- •24 Object inheritance (or delegation)
- •295 1.4) What Is a Meta-Class? (Object-Oriented Technology)
- •228 [Booch 91, p. 45] defines: "Encapsulation is the process of hiding all of the
- •912 Polymorphism is the ability of an object (or reference) to assume (be replaced
- •702 See also section 3.7, the Annotated Bibliography, and appendix d. The
- •120 Application Objects - In the Object Model
- •210 Prototype theory in the context of ooa and ood.
- •180 Derived class, parent class
- •400 Specify required attributes of a matching object (see sections 2.1, 2.7 and
- •2282 Garbage collection (gc) is a facility in the run-time system associated with a
- •1540 From a joint proposal (named "corba") of Hewlett-Packard, ncr Corp.,
- •170 Inheritance. This is an example of dynamic binding, which replaces a
- •1519 1) The Object Request Broker, or key communications element, for
- •714 Of externally observable behavior; a complete, consistent, and feasible
- •749 (User-)environment). The product, or resultant model,
- •302 The Meta-Class can also provide services to application programs, such as
- •1511 In late 1990 the omg published its Object Management Architecture
- •621 Term "multi-method") consider the functional and receiver based forms
- •1617 Between applications on different machines in heterogeneous
- •192 Objects contain fields, methods and delegates (pseudo parents), whereas
- •159 Function taking an object of the record type, called the receiver, as the
- •1346 Information, updates to Release 1.1 of The Object Database Standard:
- •458 Or change parents from objects (or classes) at run-time. Actors, clos, and
- •774 Should be made into a public standard, perhaps to be adopted by the omg. The
- •140 Objects [Kim 89, ch 19 and Yaoqing 93]. Simple static approaches are found in
- •18 A survey by Deborah j. Armstrong of nearly 40 years of computing literature identified a number of "quarks", or fundamental concepts, found in the strong majority of definitions of oop.
- •18 A survey by Deborah j. Armstrong of nearly 40 years of computing literature identified a number of "quarks", or fundamental concepts, found in the strong majority of definitions of oop.
- •168 [Stroustrup 90] covers the implementation details of virtual member functions
- •220 Parents when certain predicates are true. This can support a types
- •148 In more conventional languages to fully emulate this style of dynamically typed
- •2052 - Naming - network implementation of X.500 directory
- •2082 2 V1.X. Development
- •2182 Functionality than specified by the X.500 standard. Because dome goes
- •2191 - True messaging for workflow management and edi
- •1166 Used for assignment compatibility forcing an assigned object to inherit
- •2065 Registering services and entities in a distributed
- •1541 HyperDesk Corp., Digital Equipment Corp., Sun Microsystems and Object
- •2038 Toolkits (others are planned for future release) --
- •2434 Testing of Object-Oriented Programming (toop) faq
- •863 See also [Yourdon 92], [Wilkie 93], and [Booch 94] for discussions on this
- •1465 [Wilkie 93] summarizes, compares, and provides examples of Booch, Wirfs-Brock,
- •2311 Length, include file nesting and macro stack depth. This causes
- •2257 Optical or magnetic media containing all files required to load and
- •2489 Bezier, Boris, "Software Testing Techniques", 2nd edition, Van Nostrand
- •602 Notations for invoking a method, and this invocation can be called a message
- •1776 Object-communication mechanism across heterogeneous networks by using the
- •1391 It covers extensible objected-oriented programming from hardware up.
- •1317 Structured subobjects, each object has its own identity, or object-id (as
- •434 1.9) Does Multiple Inheritance Pose Any Additional Difficulties? (Object-Oriented Technology)
- •1751 Hp believes it is best positioned to help customers take advantage of
- •2709 One. This is a beta release and _should_ compile on any posix.1 system.
- •660 Dominate and double dispatch can be suffered, or an embedded dynamic typing
2052 - Naming - network implementation of X.500 directory
2082 2 V1.X. Development
2175 - CCITT X.500
2182 Functionality than specified by the X.500 standard. Because dome goes
z
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
1720 electra.ps.Z
2603 papers. Get "toop.ps.Z" for A4 paper and "toopus.ps.Z" for
2615 papers. Get "tools.ps.Z" for A4 paper formatting or get
2616 "toolsus.ps.Z" for US letter formatting.
2626 papers. Get "guide.ps.Z" for A4 paper formatting or get
2627 "guideus.ps.Z" for US letter formatting.
2637 papers. Get toopinht.ps.Z" for A4 paper formatting or get
2638 "toopinhtus.ps.Z" for US letter formatting.
2707 etet1.10.1.tar.Z". They are looking for
ability
457 More specifically, dynamic inheritance refers to the ability to add, delete,
912 Polymorphism is the ability of an object (or reference) to assume (be replaced
1023 "Polymorphism" means the ability to take several forms. In object-oriented
1024 programming, this refers to the ability of an entity to refer at run-time to
1037 oriented programming". Furthermore, the ability to call a variety of
1210 Generics (or Templates in C++) refer to the ability to parameterize types
1321 as well as the ability to have a strong equivalence with object-oriented
1810 -- easier deployment, with the ability to run multiple HP
1943 With Orbix Version 1.2 IONA has added the ability to dynamically load objects
2178 provides the ability to find an object, register an object, register
added
15 Object-oriented features have been added to many existing languages during that time, including Ada, BASIC, Fortran, Pas cal, and others. Adding these features to languages that were not initially designed for them often led to problems with compatibility and maintainability of code.
138 approach with an added layer of indirection to Smalltalk's handles is found
173 variants to be added without modifying client code (which causes higher defect
203 parents (as any other member) can be added or changed dynamically, providing
623 number of new mechanisms added to COMMON LISP" [Kim ch 4, p70 (D. Moon)].
1091 Dynamic binding allows new objects and code to be interfaced with or added to
1249 object can be added to the delegate list, giving dynamic inheritance (of a
1251 inheritance" in which fields and methods can be added and deleted from objects.
1943 With Orbix Version 1.2 IONA has added the ability to dynamically load objects
2439 to the Software section. Also a couple of articles added to the
al
55 Challenges of object-oriented design are addressed by several methodologies. Most common is known as the design patterns codified by Gamma et al.. More broadly, the term "design patterns" can be used to refer to any general, repeatable solution to a commonly occurring problem in software design. Some of these commonly occurring problems have implications and solutions particular to object-oriented development.
738 underlying theory, and emerging technology within the domain." - Kang et al.
1416 Rumbaugh et al. [Rumbaugh 91]
1420 Wirfs-Brock et al. [Wirfs-Brock 90]
1447 [van den Goor et.al., 1992]
1453 [Hong et.al. 1992]
1467 Wasserman et al, Rumbaugh, Reenskaug et al, and Colbert.
1482 Rumbaugh, J. et.al. - Object-oriented modeling and design, 1991.
1485 Wirfs-Brock, R. et.al. - Designing object-oriented software, 1990.
approaches
63 Both object-oriented programming and relational database management systems (RDBMSs) are extremely common in software today. Since relational databases don't store objects directly (though some RDBMSs have object-oriented features to approximate this), there is a general need to bridge the two worlds. The problem of bridging object-oriented programming accesses and data patterns with relational databases is known as Object-Relational impedance mismatch. There are a number of approaches to cope with this problem, but no general solution without downsides.[20] One of the most common approaches is object-relational mapping, as found in libraries like Java Data Objects and Ruby on Rails' ActiveRecord.
74 A study by Potok has shown no significant difference in productivity between OOP and procedural approaches.
134 based, capability-based, and simple static-based approaches. Descriptor-
135 based approaches (e.g. Smalltalk handles) allow powerful dynamic typing, as
136 do the capability-based approaches which are typically found in object-
140 objects [Kim 89, ch 19 and Yaoqing 93]. Simple static approaches are found in
144 Descriptor-based approaches can have pointer semantics and can be statically
293 upon unsatisfactory results, and finally the latter if the first two approaches
1119 statically-typed OO languages provide polymorphism. Some approaches provide
classification
54 ECMAScript language. JavaScript is perhaps the best known prototype- based programming language, which employs cloning from prototypes rather than inheriting from a class. Another scripting language that takes this approach is Lua. Earlier versions of ActionScript (a partial superset of the ECMA-262 R3, otherwise known as ECMAScript) also used a prototype-based object model. Later versions of ActionScript incorporate a combination of classification and prototype-based object models based largely on the currently incomplete ECMA-262 R4 specification, which has its roots in an early JavaScript 2 Proposal. Microsoft's JScript.NET also includes a mash-up of object models based on the same proposal, and is also a superset of the ECMA-262 R3 specification.
206 classification where any object can be inherited from or cloned to serve as a
268 A class is a general term denoting classification and also has a new meaning
278 Original Aristotlean classification defines a "class" as a generalization of
289 [Booch 94, 4.2] proposes 3 views of classification as useful in OO analysis and
367 Inheritance provides a natural classification for kinds of objects and allows
370 classification, and generalization to understand and deal with the complexities
525 use of inheritance for typical classification. Representation "roles" can be
927 ad-hoc. Cardelli and Wegner followup with another classification scheme,
1012 perhaps IP could be further divided in C+W's above classification.]
complexity
113 driven design. Jacobson also calls for managing complexity with specialized
172 and program complexity (fewer nested programming constructs) and allowing
482 by reducing the real-world's inherent complexity.
638 and cohesion, multiple-polymorphism reduces program complexity by avoiding
640 complexity, as code complexity doesn't grow linearly with lines of code per
1095 program complexity by replacing a nested construct (switch statement) with a
1097 and loose coupling. Another benefit is that code complexity increases not
1099 methods reduces program complexity considerably, even further that removing
1762 reduces the complexity of developing distributed applications so programmers
components
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
875 processing system and software products development as integrated components.
972 components."
1747 HP ORB Plus and HP Distributed Smalltalk are major components of HP's
1773 HP ORB Plus consists of several components: the Distributed Object
2218 DOME Software System Components
2356 Program components frequently need knowledge of an entire program to
2392 manually managed components and libraries often use incompatible memory
2405 Any components or libraries that use containers with different memory
2647 components such as windows, cursors, or scroll bars. The filein
cs
82 Carnegie-Mellon University Professor Robert Harper in March 2011 wrote: "This semester Dan Licata and I are co-teaching a new course on functional programming for first-year prospective CS majors... Object-oriented programming is eliminated entirely from the introductory curriculum, because it is both anti-modular and anti-parallel by its very nature, and hence unsuitable for a modern CS curriculum. A proposed new course on object- oriented design methodology will be offered at the sophomore level for those students who wish to study this topic."
131 **There is a patterns mailing list, email: patterns-request@cs.uiuc.edu,
1489 Sjaak Brinkkemper (sjbr@cs.utwente.nl), which we will forward to the
1698 > CS Dept. University of Zurich, Switzerland. maffeis@ifi.unizh.ch
1706 CS Dept. University of Zurich, Switzerland. maffeis@ifi.unizh.ch
1846 From: rcbc@cs.cornell.edu (Robert Cooper)
2335 anonymous ftp (cs.utexas.edu:pub
2520 are dhoffman@csr.uvic.ca and pstropp@cs.uq.oz.au. Describes an
2654 TreeLW1.1" from st.cs.uiuc.edu.
defines
71 Responsibility-driven design defines classes in terms of a contract, that is, a class should be defined around a responsibility and the information that it shares. This is contrasted by Wirfs-Brock and Wilkerson with data-driven design, where classes are defined around the data-structures that must be held. The authors hold that responsibility-driven design is preferable.
98 in depth. [Martin 92, p 241] defines: "An "object" is anything to which a
100 to certain objects in our awareness". [Rumbaugh 91] defines: "We define an
102 the problem at hand." [Shlaer 88, p 14] defines: "An object is an abstraction
228 [Booch 91, p. 45] defines: "Encapsulation is the process of hiding all of the
230 [Coad 91, 1.1.2] defines: "Encapsulation (Information Hiding). A principle,
278 Original Aristotlean classification defines a "class" as a generalization of
559 Stroustrup's first edition of [Stroustrup 91, '86 p. 37] defines object based
1371 Ouverture Project (ESPRIT funded OMG IDL defines inter-module interfaces)
2028 - defines and implements a comprehensive enterprise
descriptions
291 (conceptual descriptions), and prototype theory (resemblance to an exemplar).
1703 CORBA Implementation Descriptions: The ELECTRA Toolkit
1724 CORBA Implementation Descriptions: HD_DOMS
1737 CORBA Implementation Descriptions: HP ORB Plus and HP Distributed Smalltalk
1845 CORBA Implementation Descriptions: Iris RDOM
1866 CORBA Implementation Descriptions: Object-Oriented Technologies DOME
1918 CORBA Implementation Descriptions: ORBELINE - The SMART Object Request Broker
1929 CORBA Implementation Descriptions: Orbix
2008 CORBA Implementation Descriptions: NCR 'Cooperative Frameworks' -- a Distributed Object Foundation
2120 CORBA Implementation Descriptions: SUITESOFTWARE (SuiteDOME)
details
168 [Stroustrup 90] covers the implementation details of virtual member functions
229 details of an object that do not contribute to its essential characteristics."
663 handling, like C++ friends, usually by allowing representation details of more
718 behavior and adding details needed for actual computer system implementation,
719 including human interaction, task management, and data management details."
780 life-cycle models and their use. Humphrey also details Worldy and Atomic
988 extensional view and set union with an intensional view. Details are left as
1562 details are given at the end of this paper.
1772 HP ORB PLUS DETAILS
1818 TECHNICAL DETAILS AND AVAILABILITY
dispatch
21 Dynamic dispatch – when a method is invoked on an object, the object itself determines what code gets executed by looking up the method at run time in a table associated with the object. This feature distinguishes an object from an abstract data type (or module), which has a fixed (static) implementation of the operations for all instances. It is a programming methodology that gives modular component development while at the same time being very efficient.
26 Similarly, in his 2003 book, Concepts in programming languages, John C. Mitchell identifies four main features: dynamic dispatch, abstraction, subtype polymorphism, and inheritance.Michael Lee Scott in Programming Language Pragmatics considers only encapsulation, inheritance and dynamic dispatch.[16]
36 abstract data types (which have existential types) allow the definition of modules but these do not support dynamic dispatch
642 dispatch, a fancy name for single dispatch after a call, which only provides
644 ignoring the inherent type of parameters in messaging. Double dispatch is
653 type of "one" would be used with double dispatch! In the author's opinion,
654 this is a serious shortcoming. Further, double dispatch would only allow
660 dominate and double dispatch can be suffered, or an embedded dynamic typing
dynamically
11 The Smalltalk language, which was developed at Xerox PARC (by Alan Kay and others) in the 1970s, introduced the term object-oriented programming to represent the pervasive use of objects and messages as the basis for computation. Smalltalk creators were influenced by the ideas introduced in Simula 67, but Smalltalk was designed to be a fully dynamic system in which classes could be created and modified dynamically rather than statically as in Simula 67.[9] Smalltalk and with it OOP were introduced to a wider audience by the August 1981 issue of Byte Magazine.
148 in more conventional languages to fully emulate this style of dynamically typed
175 Virtual members in dynamically typed languages are more flexible because
203 parents (as any other member) can be added or changed dynamically, providing
610 if done dynamically (true dynamic binding). Statically typed dynamic binding
1032 as found in several dynamically typed OO languages such as Actors, CLOS,
1053 dynamically typed languages, polymorphic objects are passed messages and will
1077 lookup is performed (bound) at run-time (dynamically). This is often desired
1943 With Orbix Version 1.2 IONA has added the ability to dynamically load objects
2179 the message interface to an object, and dynamically invoke an object.
file
1390 as well as basic OS i ssues such as memory, file, tasking management.
1570 help (how to use file server)
1572 get <file> (get files returned by index)
1576 size <segment size> (max file size to send)
1946 traditional flat file databases, relational databases or object oriented
2138 and file systems; access and distribute data; guarantee system
2311 length, include file nesting and macro stack depth. This causes
2319 are the Interviews C++ graphics library and the Unix file system (the
2541 Copies of the postscript file can be obtained by sending email
2650 4.1 and VisualWorks 1.0). To get it ftp the file
implemented
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
299 picture Meta-Classes. Classes must be implemented in some way; perhaps with
363 systems, which often refer to systems implemented in terms of themselves, or
974 Implicit parametric polymorphism can be implemented with type inferencing
1061 typed subtype polymorphism, as provided in Emerald, can be implemented
1118 implemented with tables of function pointers and offsets), and is how
1395 ETHOS was implemented as an operating system for the Ceres computers
1898 implemented to user-specific requirements.
2089 object services can be implemented directly in C++)
mechanism
77 Paul Graham has suggested that the purpose of OOP is to act as a "herding mechanism" that keeps mediocre programmers in mediocre organizations from "doing too much damage". This is at the expense of slowing down productive programmers who know how to use more powerful and more compact techniques.
216 message passing mechanism (as with dynamic scoping) than inheritance, which
245 mechanism with public, private and protected members. Public members (member
524 hierarchy "creation" mechanism, however this loses polymorphism and loses the
884 powerful dynamic typing mechanism (although these existed to some extent in
1759 the Open Software Foundation(tm) as its transport mechanism. DCE is
1776 object-communication mechanism across heterogeneous networks by using the
1803 storage mechanism to facilitate the reuse of objects.
2064 - Dynamic Service Location - provides a mechanism for
2068 - Dynamic Service Activation - provides a mechanism for
meyer
65 OOP can be used to associate real-world objects and processes with digital counterparts. However, not everyone agrees that OOP facilitates direct real-world mapping (see Negative Criticism section) or that real-world mapping is even a worthy goal; Bertrand Meyer argues in Object-Oriented Software Construction that a program is not a model of the world but a model of some part of the world; "Reality is a cousin twice removed". At the same time, some principal limitations of OOP had been noted. For example, the Circle-ellipse problem is difficult to handle using OOP's concept of inheritance.
887 [Meyer 88] contains a brief summ
902 Author, Strachey, Cardelli and Wegner, Booch, Meyer, Stroustrup, and Rumbaugh.
1022 > Meyer's Definition [Meyer 88, sect. 10.1.5 Polymorphism]:
1027 [The Author notes Meyer has a following section 10.1.7 on Static Type,
1030 Meyer is clear between the concept and the Eiffel realization in his
1191 Abstract classes ([Stroustrup 91] and [Meyer 88]) in typing provide a facility
1422 Meyer [Meyer 88]
2327 [1] "Object-Oriented Software Construction" by Meyer puts the argument
modules
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
33 Decoupling refers to careful controls that separate code modules from particular use cases, which increases code re-usability. A common use of decoupling in OOP is to polymorphically decouple the encapsulation (see Bridge pattern and Adapter pattern) - for example, using a method interface which an encapsulated object must satisfy, as opposed to using the object's class.
36 abstract data types (which have existential types) allow the definition of modules but these do not support dynamic dispatch
46 Languages called "pure" OO languages, because everything in them is treated consistently as an object, from primitives such as characters and punctuation, all the way up to whole classes, prototypes, blocks, modules, etc. They were designed specifically to facilitate, even enforce, OO methods. Examples: Scala, Smalltalk, Eiffel, JADE, Emerald.
1196 for loosely coupled modules and in distributed programming [Black 87].
2298 modules must co-operate closely. This leads to a tight binding
2299 between supposedly independent modules.
2468 optimizations, etc. This means that testing modules must be
2469 constructed in a way which is recognized as correct and the modules
network
1771 make requests and receive responses across a distributed network.
1906 - network monitoring & analysis,
1912 and network security; however, DOME does allow stream operators
2033 over a network
2049 systems and network operating systems
2052 - Naming - network implementation of X.500 directory
2074 - Network Configuration Tools - simplifies creation of
2076 in a multiple domain heterogeneous network.
2127 systems, applications, databases, network protocols, and the like.
2137 differences between operating systems, network protocols, databases,
objective-c
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
386 Objective-C, etc.), lisp-based (CLOS, Flavors, Scheme, etc.), and Pascal-based
608 considered part of the selector in Smalltalk (and hence Objective-C).
688 Objective-C, and etc.) and several possible known selectors together with the
1128 Many languages provide dynamic typing: Smalltalk, Self, Objective-C, and etc.
1256 Next's NextStep OS provides delegation using Objective-C, providing an example
1305 Objective-C (http:
1309 Objective-C
1856 Objective-C, and C++, and runs on most Unix workstations. RDOM is currently
1860 the Smalltalk and Objective-C language interfaces is expected in June.
requirements
176 static typechecking requirements are dropped. See section 2.5.
548 following requirements:
746 (from its requirements, domain and environment) from a user-oriented or domain
750 of OOA specifies a complete system and a complete set of requirements and
1443 Bailin OO requirements specification, Coad-Yourdon OOA, Shlaer-Mellor OOA,
1554 3) End-User Requirements;
1898 implemented to user-specific requirements.
2261 Configuration Requirements
2262 Disk space and memory requirements are dependent on the installation
2264 determine configuration requirements for particular computer systems.
server
1563 3.8.3) Mail Server Access (OMG
1567 Information via Mail Server:
1568 Send the following commands in a letter to the mail server.
1569 mail omg_server@omg.org
1570 help (how to use file server)
1573 log <info> (logs info on server)
1584 mail omg_server@omg.org
2054 - Logging - provides local and server based error
2086 server system
2230 to know the physical location of data, the server of access, or the
service
1728 storage, a Kerberos-based authentication service, a location service, a
2053 provides object naming service
2064 - Dynamic Service Location - provides a mechanism for
2066 system and invoking targeted services based on service
2068 - Dynamic Service Activation - provides a mechanism for
2071 - Event Service (Release 3.1) - Implements an OMG
2073 compliant event service
2181 (ORB) and contains a directory and name service that provides more
2195 - Different levels of messaging service for positive
specialized
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
113 driven design. Jacobson also calls for managing complexity with specialized
328 of specialized Meta-Classes for classes. There is still a Meta-Class as in
329 a 3 Level System, but as a class it also has a specialized Meta-Class, the
509 operations available (set operations are quite common in specialized systems).
534 specialized behavior. All routines in Smalltalk are overridable and non-
625 Multiple-polymorphism allows specialized functions or methods to be defined to
634 The above functions are specialized to each of the cases required allowing
966 where each instantiation creates a specialized version of the code allowing
1057 overrode the virtual method from its base class, providing specialized behavior
storage
1526 the logical modeling and physical storage of objects; and
1728 storage, a Kerberos-based authentication service, a location service, a
1803 storage mechanism to facilitate the reuse of objects.
2287 Without GC programmers must explicitly deallocate dynamic storage when
2290 1: Bugs due to errors in storage deallocation are very hard to find,
2293 storage cannot be made by the programmer. Drawing editors and
2296 3: An object which is responsible for deallocating storage must be
2297 certain that no other object still needs that storage. Thus many
2306 6: Because keeping track of storage is extra work, programmers often
2323 storage deallocation is probably as high as GC. GC algorithms are
supports
264 receiver in per-object protection. This supports a subtyping model, as any
549 - It supports objects that are data abstractions with an interface of named
1366 Choices (research OS, UofI, C++, supports SVR4, See Appendix E, Papers)
1368 Mach (CMU, supports BSD 4.3, really message-based)
1549 arenas besides the distributed system problem, the Group supports Special
1605 a methodology that supports modular production of software;
1610 supports their goals. The OMA publication outlines the
1714 in C++. It supports object-groups, virtual synchrony, multithreading
1761 without modification -- on any other system that supports DCE. HP ORB Plus
2034 - supports TCP
test
1729 set of base classes to speed development, and a test script language.
1859 RDOM has been at beta test sites since January. General release of
2471 As soon as one major class library vendor starts to ship real test code
2611 execution of test cases for OOP. These tools assume a
2645 specific classes that test non-interactive objects such as trees,
2681 *Graphical test coverage to highlight any code not executed during test runs
2682 *Intuitive GUI for easy test analysis
2699 A group of volunteers is building a C++ test harness for the automated
2701 Test Environment Toolkit). To join the group of volunteers, send email to
typical
115 Ordinary Objects - Typical OOPL objects
118 Frameworks*(Typical) - Abstract MO meant for reuse and extension
119 Patterns** (Typical) - Framework-like, crsp. classes and comm patterns only
199 concept, will result. Typical 1 Level objects can contain any number of
202 thus performing the classical role of a class. In typical prototyping systems,
525 use of inheritance for typical classification. Representation "roles" can be
540 any member to be redefined and not just methods, as is typical.
1123 Static typing is more efficient and reliable, but loses power. Typical
1176 (subclass polymorphism), as is typical in most OOPLs. Dropping this
1224 While generics have many advantages, typical limitations include a static
university
82 Carnegie-Mellon University Professor Robert Harper in March 2011 wrote: "This semester Dan Licata and I are co-teaching a new course on functional programming for first-year prospective CS majors... Object-oriented programming is eliminated entirely from the introductory curriculum, because it is both anti-modular and anti-parallel by its very nature, and hence unsuitable for a modern CS curriculum. A proposed new course on object- oriented design methodology will be offered at the sophomore level for those students who wish to study this topic."
1450 Center of Telematics and Information Technology, University of Twente,
1452 State University, Atlanta, USA, 1992, 163 pages.
1559 Any company, university
1698 > CS Dept. University of Zurich, Switzerland. maffeis@ifi.unizh.ch
1706 CS Dept. University of Zurich, Switzerland. maffeis@ifi.unizh.ch
2596 Engineering and Computer Sciences (SECS), University of Durham,
2609 Computer Science (SECS), University of Durham, Durham,
2621 University of Durham, Durham, England. Discusses different
2631 Engineering and Computer Science (SECS), University of Durham,
unix
1805 modification on HP, Sun and IBM UNIX(R) system-based workstations. They
1856 Objective-C, and C++, and runs on most Unix workstations. RDOM is currently
1875 UNIX, Windows, Windows NT, OS
1878 SunOs, Solaris, HP-UX, SGI Unix, Stratus FTX,
2077 NCR Cooperative Frameworks run on multiple UNIX platforms,
2078 including HP-UX, Sun Solaris, NCR 3000 UNIX and NCR
2079 StarServer UNIX SVR4; and on MS Windows 3.1. Cooperative
2215 DOME runs on the major UNIX platforms as well as in other interactive
2319 are the Interviews C++ graphics library and the Unix file system (the
2448 I work for a Unix software house, Qualix Group, in the US. Here is
user
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
1079 programming and user interaction (e.g. GUIs). Examples can be found in
1219 or user defined type, or even a Stack of Stacks of ... Another example is
1332 interactive user interface facilities, as found in a fully supported OODBMS.
1597 commentaries from software industry leaders, informative user
1689 Windows 3.1, 12 user license: $99.
2229 distributed data management transparent, so that the user never needs
2382 execution to make a compile-time determination of the last user of an
2385 different threads) makes it impossible to statically determine the last user
2646 collections, or numbers. It is not suitable for testing user interface
yourdon
754 adds OO techniques to the traditional structured analysis principles of Yourdon
759 [Yourdon 92] provides a critique, although may only refer to their earlier
779 See [Humphrey 89] and [Yourdon 92] for a few of many discussions on software
863 See also [Yourdon 92], [Wilkie 93], and [Booch 94] for discussions on this
876 [Yourdon 92] even calls for "global modeling"!
1403 Yourdon [Coad 91]
1442 OOA, OOD, conventional analysis, conventional design, DeMarco SA, Yourdon SA,
1466 Hood, Coad and Yourdon, Winter Partners, Shlaer and Mellor, Jacobson,
1472 Coad, P., and Yourdon, E. - Object-oriented analysis (2nd edition), 1991a.
1473 Coad, P., and Yourdon, E. - Object-oriented design, 1991b.
abstraction
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
26 Similarly, in his 2003 book, Concepts in programming languages, John C. Mitchell identifies four main features: dynamic dispatch, abstraction, subtype polymorphism, and inheritance.Michael Lee Scott in Programming Language Pragmatics considers only encapsulation, inheritance and dynamic dispatch.[16]
32 Abstraction
101 object as a concept, abstraction or thing with crisp boundaries and meaning for
102 the problem at hand." [Shlaer 88, p 14] defines: "An object is an abstraction
571 Abstraction
894 encapsulation and abstraction (higher cohesion
accessible
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
247 Pop methods will be public. Private members are only accessible from within
249 private. Protected members are accessible from within a class and also from
255 For another example, Smalltalk's class instance variables are not accessible
314 All Objects are instances of a Class but Classes are not accessible to
350 Meta-Classes accessible to users [Kiczales 92, Paepcke 93]. In CLOS
580 In C++ no, because C++ classes are not instances of an accessible class (a
581 Meta-Class) and because C++ classes are not accessible to programs. Classes
assignment
143 in 1989 through the notion of assignment attempt, also known as type narrowing.
379 for differential programming. Inheritance can also double for assignment
499 which is a member of (inherits from) a class is polymorphically assignment
501 class. Such assignment can result in the loss of an object's dynamic type in
998 polymorphism with respect to assignment (and initialization, or replacement if
1000 assignment is based on actual object membership in that type (often of the CLOS
1049 object (pointer or reference (or such parameter)) is assignment compatible with
1147 types during assignment (and hence for parameters) and therefore provides
1166 used for assignment compatibility forcing an assigned object to inherit
author's
514 but in the author's opinion many of their complaints are easily answered. In
653 type of "one" would be used with double dispatch! In the author's opinion,
657 real-world programming situations, unnecessarily. In the author's opinion,
812 [Author's note: The spiral model is often incremental and may waterfall if
911 > Author's Definition:
973 Author's Notes:
2278 written for the FAQ by Paul Johnson and the second is from the FAQ author's
2511 J. Vol 11, No 3. One author's email address is
2528 The Smalltalk Report, Vol. 1, No. 9, pp.3-7. The author's
availability
716 operational characteristics (e.g. reliability, availability, performance)".
1531 Proposals, requesting detailed technical and commercial availability
1818 TECHNICAL DETAILS AND AVAILABILITY
1977 Availability
1979 The full Orbix availability and release schedule looks like:
2012 NCR ANNOUNCES BETA AVAILABILITY
2043 applications for improved availability
2091 developers with general availability set for December, 1993;
2093 with general availability set for 2Q 1994
b
703 classified bibliography in [Booch 94] also contains entries on OOA(B), OOD(F)
796 [Coad 91b] presents the following development cycle breakdown:
1222 See [Booch 87b] for several examples in Ada and [Stroustrup xx] and [Murray
1313 See also Appendices B and E and the comp.database.object newsgroup.
1333 Appendix B also contains references for object-oriented interfaces to
1473 Coad, P., and Yourdon, E. - Object-oriented design, 1991b.
1475 Henderson-Sellers, B. and Edwards, J.M. - Methodology for Object-oriented
2349 3.9b) Why is Garbage Collection Necessary for Object-Oriented Programming? (Object-Oriented Technology)
2398 b) Switches indicating deletion. Many applications must clear the switch to
beta
539 not have to be declared. Eiffel and BETA are examples of languages allowing
886 BETA a followup to Simula (by its original designers).
1299 BETA
1859 RDOM has been at beta test sites since January. General release of
1965 3.1 is now in beta. In January 1994, IONA and SunSoft Inc. signed an
1970 just entered beta testing. Work is underway on Orbix-FT, integration with
1995 Microsoft Windows 3.1 Visual C++ In Beta
2012 NCR ANNOUNCES BETA AVAILABILITY
2709 one. This is a beta release and _should_ compile on any POSIX.1 system.
business
872 found in [Jacobson 92], and along with recent business process "reengineering"
1534 by Technical and Business committees to review these responses, the
1741 PALO ALTO, Calif.--(BUSINESS WIRE) via First! -- Hewlett-Packard Company
1754 business benefit, and offers worldwide support and training programs,
1793 applications for retailers provide the means to a competitive business edge.
1834 HP Apollo 9000 Series 700 workstations and HP 9000 Series 800 business
1839 business, engineering, science, medicine and education in approximately 110
2113 NCR, AT&T's computer business, brings computing and
2251 education. The broad technical and business systems background of our
change
421 by making a small change to a class. Creating a subclass to alter a method
452 Dynamic inheritance allows objects to change and evolve over time. Since base
458 or change parents from objects (or classes) at run-time. Actors, CLOS, and
893 OOP package, naturalness (our "object concept"), resistance to change,
896 On resistance to change, system objects change infrequently while processes
1029 of an object can ever change. Only a reference can be polymorphic: ...".
1034 change its class.]
2438 Last revised on 93.10.27. The most notable change is in the additions
coad
230 [Coad 91, 1.1.2] defines: "Encapsulation (Information Hiding). A principle,
555 [Coad 91] provides another model:
710 [Coad 91]
796 [Coad 91b] presents the following development cycle breakdown:
1402 Coad
1403 Yourdon [Coad 91]
1466 Hood, Coad and Yourdon, Winter Partners, Shlaer and Mellor, Jacobson,
1472 Coad, P., and Yourdon, E. - Object-oriented analysis (2nd edition), 1991a.
1473 Coad, P., and Yourdon, E. - Object-oriented design, 1991b.
contact
1345 addresses and contact information for ODBMS vendors, ODMG membership
1376 For the Spring Papers (free), Contact:
1493 3.8.1) Contact Information (OMG
1497 Contact Person: Richard Soley (technical director) soley@omg.com
1634 Contact documents@omg.org or omg_documents@omg.org for more of the same..
1646 Contact:
2107 Contact Name
2668 For more information contact IPL:
2691 contact Paul Townsend, townsend@mprgate.mpr.ca.
context
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
96 (in context, this is "outside the computer domain". A more conventional
210 prototype theory in the context of OOA and OOD.
269 in object-oriented methods. Within the OO context, a class is a specification
284 [Booch's definition in the context of OOD]
748 system and its context
1020 [The author notes Booch's definition above is clearly in the context of
1102 Yes (but be careful of context). To use C++ terminology, an object (not
1253 piece by piece at run-time, although the term "prototyping" in the context of
control
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
70 OOP was developed to increase the reusability and maintainability of source code. Transparent representation of the control flow had no priority and was meant to be handled by a compiler. With the increasing relevance of parallel hardware and multithreaded coding, developer transparent control flow becomes more important, something hard to achieve with OOP.
122 Control - Introduced in design for control purposes
475 default. This allows a finer granularity of control and consistent name
834 leading to statistical (process) control and sustained improvement. Watts S.
2204 control
2387 clear order of execution. Other dynam ic control structures, such as
easy
298 must have a class (in classical OO anyway). Compilers provide an easy way to
305 timers. In Smalltalk, the situation is more complex. To make this easy, refer
1252 This makes for easy "prototyping", which allows for objects to be constructed
1768 provide a distributed computing environment that's easy to administer. The
2114 communications solutions together to provide people easy
2125 struggle to provide easy access to data while maintaining and
2429 computer programming easy enough for children. The idea was that manipulating
2659 making the tool exceptionally easy to use and productive in
2682 *Intuitive GUI for easy test analysis
extension
12 In the 1970s, Kay's Smalltalk work had influenced the Lisp community to incorporate object- based techniques that were introduced to developers via the Lisp machine. Experimentation with various extensions to Lisp (like LOOPS and Flavors introducing multiple inheritance and mixins), eventually led to the Common Lisp Object System (CLOS, a part of the first standardized object-oriented programming language, ANSI Common Lisp), which integrates functional programming and object-oriented programming and allows extension via a Meta- object protocol. In the 1980s, there were a few attempts to design processor architectures that included hardware support for objects in memory but these were not successful. Examples include the Intel iAPX 432 and the Linn Smart Rekursiv.
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
118 Frameworks*(Typical) - Abstract MO meant for reuse and extension
287 The intension of a class is its semantics and its extension is its instances
377 programming by extension (as opposed to programming by reinvention
568 object facility. Separate type system support is another extension.
1140 appendixes for an experimental dynamic extension to ML, Alcool-90 and [Cardelli
1200 Owl, an experimental C++ extension (See Appendix E,
2694 that is called tcat++. It is an extension of SRI's tcat program.
http
775 .8 docs can be found online from the Rational home page, http:
846 CMM documentation is available online from: http:
1279 Java (comp.lang.java, http:
1282 http:
1291 Python (new WWW, see http:
1305 Objective-C (http:
1342 WWW: http:
1685 http:
2346 [4] Geodesic Systems provides GC for C and C++. See http:
important
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
45 Simula (1967) is generally accepted as the first language to have the primary features of an object-oriented language. It was created for making simulation programs, in which what came to be called objects were the most important information representation. Smalltalk (1972 to 1980) is arguably the canonical example, and the one with which much of the theory of object-oriented programming was developed. Concerning the degree of object orientation, following distinction can be made:
70 OOP was developed to increase the reusability and maintainability of source code. Transparent representation of the control flow had no priority and was meant to be handled by a compiler. With the increasing relevance of parallel hardware and multithreaded coding, developer transparent control flow becomes more important, something hard to achieve with OOP.
80 Steve Yegge, making a roundabout comparison with Functional programming, writes, "Object Oriented Programming puts the Nouns first and foremost. Why would you go to such lengths to put one part of speech on a pedestal? Why should one kind of concept take precedence over another? It's not as if OOP has suddenly made verbs less important in the way we actually think. It's a strangely skewed perspective."
521 latter part of section 1.9 for an example of why MI is important.
2425 and garbage collection is much too important a tool to be absent from any
2462 I just think it is important.
2464 Why is this important? If classes are really to be reused in
2590 important for OOP and describes one quality program.
kim
140 objects [Kim 89, ch 19 and Yaoqing 93]. Simple static approaches are found in
188 prototyping languages [Kim 89, ch3; Ungar 87, Sciore 89] have a more
431 [Kim 89, ch 4], make good use of mixins by invoking their methods without
462 See also [Kim 89, chs 1, 3] for a discussion and [Coplien 92] for some
566 even migrate across machines. Distributed Smalltalk's proxy objects [Kim 89,
623 number of new mechanisms added to COMMON LISP" [Kim ch 4, p70 (D. Moon)].
664 than one object to be exposed. See [Kim ch 4, pp70-71 (D. Moon)] for an
1241 See [Kim 89, ch 1,3].
1264 CLOS [Kim 89, ch 4] has a looser coupling of methods to classes and doesn't
library
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
490 as library classes have already been tested and further use provides further
1894 DOME is constructed as a C++ class library, from which ORBs
2319 are the Interviews C++ graphics library and the Unix file system (the
2471 As soon as one major class library vendor starts to ship real test code
2474 about it. If you had to recommend a class library to a committee that
2476 safer with a class library that could be auto-tested in your
2549 during the first release of their initial class library.
2642 There is a smalltalk class library in the Univ. of Illinois archives
making
45 Simula (1967) is generally accepted as the first language to have the primary features of an object-oriented language. It was created for making simulation programs, in which what came to be called objects were the most important information representation. Smalltalk (1972 to 1980) is arguably the canonical example, and the one with which much of the theory of object-oriented programming was developed. Concerning the degree of object orientation, following distinction can be made:
80 Steve Yegge, making a roundabout comparison with Functional programming, writes, "Object Oriented Programming puts the Nouns first and foremost. Why would you go to such lengths to put one part of speech on a pedestal? Why should one kind of concept take precedence over another? It's not as if OOP has suddenly made verbs less important in the way we actually think. It's a strangely skewed perspective."
321 itself (really making this a 3 1
421 by making a small change to a class. Creating a subclass to alter a method
1263 variables - with subtype polymorphism making up the difference.
1684 consider making other platforms available if enough interest. See Appendix E.
2164 customer's applications, making it possible to share information
2622 methods of making class declarations and the implications of
2659 making the tool exceptionally easy to use and productive in
microsoft
1807 3.1 or Windows NT operating systems from Microsoft(R) Corp., once
1961 out versions of Orbix for Microsoft Windows NT, Silicon Graphics IRIX and
1963 UX. IONA demonstrated a version of Orbix for Microsoft Windows 3.1 at
1964 Object World in London, England last October. Orbix for Microsoft Windows
1967 demonstrated interoperability between IONA's Orbix running on Microsoft
1993 Microsoft Windows NT Visual C++ NOW
1994 Microsoft Windows NT Borland NOW
1995 Microsoft Windows 3.1 Visual C++ In Beta
2174 - OLE Microsoft
models
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
54 ECMAScript language. JavaScript is perhaps the best known prototype- based programming language, which employs cloning from prototypes rather than inheriting from a class. Another scripting language that takes this approach is Lua. Earlier versions of ActionScript (a partial superset of the ECMA-262 R3, otherwise known as ECMAScript) also used a prototype-based object model. Later versions of ActionScript incorporate a combination of classification and prototype-based object models based largely on the currently incomplete ECMA-262 R4 specification, which has its roots in an early JavaScript 2 Proposal. Microsoft's JScript.NET also includes a mash-up of object models based on the same proposal, and is also a superset of the ECMA-262 R3 specification.
81 Rich Hickey, creator of Clojure, described object systems as over simplistic models of the real world. He emphasized the inability of OOP to model time properly, which is getting increasingly problematic as software systems become more concurrent.
764 models, and even DFD's. Booch, Jacobson, and Wirfs-Brock are examples of OO
780 life-cycle models and their use. Humphrey also details Worldy and Atomic
781 Process Models for finer grained analysis and design in the Defined Process
782 (see below) and discusses other alternatives to the task oriented models. He
1508 (*) development of command models and a common interface for the development
org
1292 www.python.org
1341 Gopher: gopher.odmg.org, port 2073
1343 www.odmg.org:3083
1350 ODMG, send an email message to info@odmg.org and you will receive an
1569 mail omg_server@omg.org
1584 mail omg_server@omg.org
1626 omg.org:pub
1634 Contact documents@omg.org or omg_documents@omg.org for more of the same..
passing
31 Message passing
216 message passing mechanism (as with dynamic scoping) than inheritance, which
595 and message passing.
603 (or message passing, see below):
609 If done statically, this can be referred to as invocation, and message passing
683 can occur with multiple-polymorphism (or even dynamic message passing).
909 polymorphous adj. having, assuming, or passing through many or various forms,
1247 on message passing where an object could delegate responsibility of a message
2380 3. Message Passing Leads to Dynamic Execution Paths
persistent
565 modern notion of relocatable, persistent and distributed objects that can
1324 Another way of looking at Object-Oriented Databases is as a persistent object
1330 lifetime and objects stored indefinitely in an OODB (which are persistent)
1331 having the longest. Persistent object stores do not support query or
1334 relational databases and see APPENDIX E, Papers, Persistent Operating Systems.
1382 See also APPENDIX E, PAPERS, Persistent Operating Systems entry.
1727 exercising objects, a bundled object database for persistent object
1899 Database distribution can be as simple persistent files,
2062 support object persistence. Persistent objects can be
platforms
1641 compliant implementation of CORBA and is available on these platforms:
1684 consider making other platforms available if enough interest. See Appendix E.
1780 platforms.
1784 interoperability of distributed applications across HP and IBM platforms.
1873 DOME provides heterogenous distribution across many platforms
2077 NCR Cooperative Frameworks run on multiple UNIX platforms,
2095 Cooperative Framework implementations on supported platforms
2126 updating a collection of incompatible hardware platforms, operating
2215 DOME runs on the major UNIX platforms as well as in other interactive
references
43 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2009)
145 typeless (or just "typeless", as in Smalltalk) where references (variables)
500 compatible with (can be used in place of) instances or references of that
1234 are generic. Russell and Haskel are more modern variants (references are
1333 Appendix B also contains references for object-oriented interfaces to
2303 and comparing whole objects rather than just references. This is a
2314 scheme each object keeps a count of references to it. When this count
2316 is inefficient (swapping two references will result in three
2401 c) Value semantics store objects rather than references, inhibiting data
research
1366 Choices (research OS, UofI, C++, supports SVR4, See Appendix E, Papers)
1432 Five Object Oriented Development Methods, Research report, HP Laboratories,
1461 Monarchi, David and Puhr, Gretchen I. A Research Typology for Object-Oriented
1468 Wirfs-Brock, R.J. and Johnson, R.E., "Surveying Current Research in Object-
1560 research institution or individual, whether
1712 Electra is a research project and not available yet.
2367 arrays and multiple inheritance). Intensive research [1] in garbage
2688 MicroTech Pacific Research (mpr.ca) has a C++ class testing tool called
2692 Software Research Inc. (625 Third St, San Francisco, CA 94107-1997,
solaris
1682 SunOS 4.x, Solaris 2.3, and OSF
1878 SunOs, Solaris, HP-UX, SGI Unix, Stratus FTX,
1959 IONA released Orbix for SunSoft Solaris and SunOS at the Object World
1968 Windows 3.1 and SunSoft's Distributed Objects Everywhere (DOE) on Solaris.
1987 Solaris 2.x SPARCompiler 3.0.2 NOW
1988 Solaris 2.x SPARCompiler 4.0 NOW
1989 Solaris 2.x GNU 2.5.7 NOW
2078 including HP-UX, Sun Solaris, NCR 3000 UNIX and NCR
2711 software will have the fewest problems on SunOS or Solaris releases.
standards
1550 Interest Groups for discussion of possible standards in other areas. These
1692 - an open system, standards compliance, object-oriented architecture,
2156 - standards compliance
2167 o Standards Compliant
2168 DOME is compliant with the following standards:
2183 beyond what many of the standards require, it makes the task of
2186 SUITESOFTWARE is a member of various standards groups and conforms
2187 its products to industry standards as they are adopted.
2275 [Covers CORBA standards with respect to OODBs]
subclasses
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
250 within subclasses (also called derived classes). A Stack's representation
259 class. All Smalltalk instance variables can be accessed by subclasses,
445 same names for instance variables of subclasses illegal.
485 available to all subclasses throughout the diagram. All attributes available
486 in Personal computers are also available to all of its subclasses. This kind
939 subtypes and subclasses (inheritance). Strachey's parametric polymorphism is
2648 includes Tree classes, Tester itself, and subclasses of Tester that are
sunos
1644 1, SunOS, ULTRIX, Digital VAX
1682 SunOS 4.x, Solaris 2.3, and OSF
1878 SunOs, Solaris, HP-UX, SGI Unix, Stratus FTX,
1959 IONA released Orbix for SunSoft Solaris and SunOS at the Object World
1983 SunOS 4.1 SPARCompiler 2.1 NOW
1984 SunOS 4.1 SPARCompiler 3.0.2 NOW
1985 SunOS 4.1 Lucid 3.1 NOW
1986 SunOS 4.1 GNU 2.5.8 NOW
2711 software will have the fewest problems on SunOS or Solaris releases.
theory
41 Attempts to find a consensus definition or theory behind objects have not proven very successful (however, see Abadi & Cardelli, A Theory of Objects[18] for formal definitions of many OOP concepts and constructs), and often diverge widely. For example, some definitions focus on mental activities, and some on program structuring. One of the simpler definitions is that OOP is the act of using "map" data structures or arrays that can contain functions and pointers to other maps, all with some syntactic and scoping sugar on top. Inheritance can be performed by cloning the maps (sometimes called "prototyping"). OBJECT:=>> Objects are the run time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle.
45 Simula (1967) is generally accepted as the first language to have the primary features of an object-oriented language. It was created for making simulation programs, in which what came to be called objects were the most important information representation. Smalltalk (1972 to 1980) is arguably the canonical example, and the one with which much of the theory of object-oriented programming was developed. Concerning the degree of object orientation, following distinction can be made:
205 term "Prototype" usually refers to prototype theory, a recent theory of
210 prototype theory in the context of OOA and OOD.
291 (conceptual descriptions), and prototype theory (resemblance to an exemplar).
738 underlying theory, and emerging technology within the domain." - Kang et al.
1015 polymorphism A concept in type theory, according to which a name (such as a
viewed
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
155 expanded types in Eiffel) can be viewed as instances of a record type,
309 All objects can be viewed as classes and all classes can be viewed as
959 Inclusion Polymorphism: an object can be viewed as belonging to many different
999 viewed in an almost symbolic way) occurs when object types may be specified and
1230 parametrically polymorphic implementation. Generics can also be viewed as a
1328 viewed as a hierarchy, with locals
vol
1436 21-32. Vol.5, No. 1, 3
1439 Methodologies. Computer, Oct 1992, Vol 25, No. 10, p 22-40
1457 Press, Hawaii) 1993, Vol. IV, pp. 689-698.
1464 Vol.35, No.9, pp35.
2339 Weiser. Software --- Practise and Experience vol 18(9), pp 807-820.
2511 J. Vol 11, No 3. One author's email address is
2528 The Smalltalk Report, Vol. 1, No. 9, pp.3-7. The author's
2572 Programming, June, 1991, Vol. 4, No. 3, pp. 10 - 27.
2588 Magazine, Vol. 2, No. 2, July-August 1992, pp17-18. SIGs
www
776 www.rational.com.
1283 www.sigs.com, See Anon FTP)
1291 Python (new WWW, see http:
1292 www.python.org
1306 www.marble.com
1342 WWW: http:
1343 www.odmg.org:3083
1686 www.pomoco.com
2347 www.geodesic.com
adding
15 Object-oriented features have been added to many existing languages during that time, including Ada, BASIC, Fortran, Pas cal, and others. Adding these features to languages that were not initially designed for them often led to problems with compatibility and maintainability of code.
43 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2009)
52 In recent years, object-oriented programming has become especially popular in dynamic programming languages. Python, Ruby and Groovy are dynamic languages built on OOP principles, while Perl and PHP have been adding object oriented features since Perl 5 and PHP 4, and ColdFusion since version 5.
73 Luca Cardelli wrote a paper titled "Bad Engineering Properties of Object-Oriented Languages" Richard Stallman wrote in 1995, "Adding OOP to Emacs is not clearly an improvement; I used OOP when working on the Lisp Machine window systems, and I disagree with the usual view that it is a superior way to program."
718 behavior and adding details needed for actual computer system implementation,
928 adding inclusion polymorphism for subtyping and inheritance.
938 C+W refine Strachey's definition by adding "inclusion polymorphism" to model
1348 adding more links to related sites, bibliographies, and a FAQ for ODBMSs.
additional
27 Additional concepts used in object-oriented programming include:
428 additional attributes or properties to other classes. They are intended to be
434 1.9) Does Multiple Inheritance Pose Any Additional Difficulties? (Object-Oriented Technology)
914 specifies slightly different or additional structure or behavior for an object,
915 and these more specific or additional attributes of an object of a base class
1822 writing distributed, object-oriented applications require additional
2205 - Implementation of additional protocols through a
2260 nominal additional cost.
advantage
196 However, one-le vel objects often play the role of classes to take advantage of
368 for the commonality of objects to be explicitly taken advantage of in modeling
487 of reuse takes advantage of the is-a-kind-of relationship. Class libraries
819 Seamlessness together with naturalness is a big advantage for consistency.
1163 efficiency by taking advantage of that representation wherever used. In many
1225 nature, which is an advantage for strong typechecking but a potential
1751 HP believes it is best positioned to help customers take advantage of
1792 executive officer of Information Advantage, Inc. "Our object-based
argument
643 switching on a single argument per call (but for 2 levels), consistently
677 class differentiated only by their formal argument types. This therefore
678 requires both static and dynamic typing, because no formal argument
680 actual argument differentiation is possible without dynamic types (as in C++
957 type parameter which determines the type of the argument for each
2327 [1] "Object-Oriented Software Construction" by Meyer puts the argument
2359 taking a container as an argument need to know of or make assumptions
2551 Makes the argument that testing of object-oriented software is
basic
15 Object-oriented features have been added to many existing languages during that time, including Ada, BASIC, Fortran, Pas cal, and others. Adding these features to languages that were not initially designed for them often led to problems with compatibility and maintainability of code.
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
48 Languages that are historically procedural languages, but have been extended with some OO features. Examples: Visual Basic (derived from BASIC), Fortran 2003, Perl, COBOL 2002, PHP, ABAP.
446 On the other hand, multiple-inheritance can be seen as required for basic
1390 as well as basic OS i ssues such as memory, file, tasking management.
1525 realising basic object functionality using the Object Request Broker -
2241 Powerbuilder,, Visual Basic,, and Uniface,. Among the CASE tools are
built
52 In recent years, object-oriented programming has become especially popular in dynamic programming languages. Python, Ruby and Groovy are dynamic languages built on OOP principles, while Perl and PHP have been adding object oriented features since Perl 5 and PHP 4, and ColdFusion since version 5.
731 be built so that the cost of the domain analysis can be amortized over the
751 external interface of the system to be built, often obtained from a domain
1604 integrated software systems. These systems should be built using
1804 Applications built using HP Distributed Smalltalk currently run without
1854 cooperating objects. RDOM is built on top of the Isis Distributed
1891 be built and tested on a single machine using local resources.
1956 built using Orbix. IONA has also extensively extended the number, and scope, of
client
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
173 variants to be added without modifying client code (which causes higher defect
432 explicitly calling them, allowing client class code to remain unchanged [Booch
1662 UX, IBM RS-6000, Data General Aviion, MS-Windows (client
1731 (which includes support for CORBA's static client interface) is available
2085 Implementation - implementation is for client
2396 delete, placing the memory management burden on the client, who must call
2466 testable during initial evaluation by the client programmer. They must
cmm
830 (CMM), a process-based TQM model for assessing the level of an organization's
832 in the US [Humphrey 89]. The CMM also serves as a 5 level improvement process
836 version of the CMM for individuals [Humphrey 95]. Next should follow a team-
838 personnel management CMM (PM-CMM).
846 CMM documentation is available online from: http:
848 CMM and
851 cmm
867 the CMM. To join the ami mailing list email to:
commonly
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
55 Challenges of object-oriented design are addressed by several methodologies. Most common is known as the design patterns codified by Gamma et al.. More broadly, the term "design patterns" can be used to refer to any general, repeatable solution to a commonly occurring problem in software design. Some of these commonly occurring problems have implications and solutions particular to object-oriented development.
510 The former is a kind of language dependent feature commonly found in object-
684 However, static analysis optimizations are commonly available in the
726 operations, objects, and structures that commonly occur in software systems
1204 pure parametric polymorphism (as is also commonly found in OO languages in
comparison
75 Christopher J. Date stated that critical comparison of OOP to other technologies, relational in particular, is difficult because of lack of an agreed-upon and rigorous definition of OOP. Date and Darwen propose a theoretical foundation on OOP that uses OOP as a kind of customizable type system to support RDBMS.
80 Steve Yegge, making a roundabout comparison with Functional programming, writes, "Object Oriented Programming puts the Nouns first and foremost. Why would you go to such lengths to put one part of speech on a pedestal? Why should one kind of concept take precedence over another? It's not as if OOP has suddenly made verbs less important in the way we actually think. It's a strangely skewed perspective."
1220 a polymorphic sort function taking a base type with a comparison operator.
1221 The function can be called with any type (containing a comparison operator).
1430 Here are some comparison studies posted to the net:
1441 and Design Methods - Comparison and Critique. IEEE-Comp, Oct, 1992, pp 22-39.
1449 A Comparison of Six Object-oriented Analysis and Design Methods. Report
1455 Comparison of Object Oriented Analysis and Design Methodologies, Hawaii
compatible
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
500 compatible with (can be used in place of) instances or references of that
1049 object (pointer or reference (or such parameter)) is assignment compatible with
1192 similar to subtype polymorphism; however, ACs require type compatible classes
1669 Object RPC compatible with OMG CORBA 1.2 spec (will compile OMG IDL and
1711 something like an Object Broker, but it is *not* CORBA compatible (yet).
2202 - Kerberos 5.4 compatible security
2370 2. Implementation Hiding is not Compatible with Manual Memory Management
compliant
1529 compliant class interfaces.
1641 compliant implementation of CORBA and is available on these platforms:
1670 generate OMG compliant code for OMG-specified languages).
1857 not CORBA compliant, but will be brought to compliance during 3Q93.
1901 DOME has a CORBA-conformant interface, and is CORBA 1.0 compliant
2073 compliant event service
2167 o Standards Compliant
2168 DOME is compliant with the following standards:
declared
251 could be declared protected allowing subclass access. C++ also allows a
301 the work of being a class. This can be declared in a class named "Meta-Class".
539 not have to be declared. Eiffel and BETA are examples of languages allowing
584 declared to be instances of a class (and class objects instances of a
676 declared in a base class may have several functions overriding it in a derived
993 parameters must still be declared and many bodies are generated.
1106 of several classes, including all of the classes its declared (or most derived)
1114 Static typing refers to types declared in a program at compile-time, so no type
difference
74 A study by Potok has shown no significant difference in productivity between OOP and procedural approaches.
541 1.15) What Is The Difference Between Object-Based And Object-Oriented? (Object-Oriented Technology)
1052 is it? To make any difference, the differing forms must have some effect. In
1101 2.4) Is There A Difference Between Being A Member Or Instance Of A Class? (Typing - Object-Oriented Technology)
1113 2.5) What Is The Difference Between Static And Dynamic Typing? (Typing - Object-Oriented Technology)
1183 difference between static and dynamic binding in OO and dynamic binding and
1263 variables - with subtype polymorphism making up the difference.
1265 distinguish a receiver, but packages can help make up the difference.
distinct
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
306 to the following listing, which is based on the number of levels of distinct
317 There are 2 kinds of distinct objects: objects and classes.
324 There are 2 kinds of distinct objects (objects and classes), with a
339 C++). There are 3 distinct kinds of objects (objects, classes, and
439 distinct parents can declare a member within a multiple inheritance hierarchy,
907 crystallographically distinct forms. 3. Zool., Bot. existence of an
963 related, but are distinct enough in implementation to justify separate
enterprise
871 Object-oriented analysis now includes "Enterprise Modeling" [Martin 92], also
1745 applications that can be distributed throughout the enterprise. HP also
2028 - defines and implements a comprehensive enterprise
2140 middleware achieves this, it makes enterprise computing a reality.
2146 application in the enterprise, accessing virtually any data.
2147 DOME - Covering the Enterprise
2153 enterprise.
2232 perspective, the enterprise is a single logical database located in
faq
1348 adding more links to related sites, bibliographies, and a FAQ for ODBMSs.
1429 inclusion of other major or new methodologies should be sent to the FAQ author.
2278 written for the FAQ by Paul Johnson and the second is from the FAQ author's
2431 Other entries or suggestions are welcome, please send to the author of the FAQ.
2433 [This entry was donated by Doug Shaker and is certainly a FAQ]
2434 Testing of Object-Oriented Programming (TOOP) FAQ
2445 Software. It is kind of like an FAQ, though it isn't organized
files
1347 ODMG-93 along with ODL lex and yacc files. In the future, we will be
1571 index (return a list of all available files)
1572 get <file> (get files returned by index)
1575 list <directory> [match] (index a directory, pattern 'match' files)
1899 Database distribution can be as simple persistent files,
2063 files, relational or object databases
2257 Optical or magnetic media containing all files required to load and
2683 *Programmatic interface to output files and cumulative code coverage
gui
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
121 Interface - E.g. GUI
1087 selected based on the actual type of object being cut (which in the GUI case is
1726 CORBA-compliant DOMS. Includes a GUI API driver for prototyping and
1905 - integral support for GUI development,
2240 with any number of third-party GUI and CASE tools. Among the GUIs are
2386 of an object. For example, event driven GUI programs frequently have no
2682 *Intuitive GUI for easy test analysis
handle
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
41 Attempts to find a consensus definition or theory behind objects have not proven very successful (however, see Abadi & Cardelli, A Theory of Objects[18] for formal definitions of many OOP concepts and constructs), and often diverge widely. For example, some definitions focus on mental activities, and some on program structuring. One of the simpler definitions is that OOP is the act of using "map" data structures or arrays that can contain functions and pointers to other maps, all with some syntactic and scoping sugar on top. Inheritance can be performed by cloning the maps (sometimes called "prototyping"). OBJECT:=>> Objects are the run time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle.
65 OOP can be used to associate real-world objects and processes with digital counterparts. However, not everyone agrees that OOP facilitates direct real-world mapping (see Negative Criticism section) or that real-world mapping is even a worthy goal; Bertrand Meyer argues in Object-Oriented Software Construction that a program is not a model of the world but a model of some part of the world; "Reality is a cousin twice removed". At the same time, some principal limitations of OOP had been noted. For example, the Circle-ellipse problem is difficult to handle using OOP's concept of inheritance.
169 in C++, which also involve an offset for the receiver to handle multiple-
336 The "class class"es handle messages to classes, such as constructors and
626 handle various cases:
1248 it couldn't handle to objects that potentially could (its delegates). Any
2365 include failure to reclaim cycles, inability to handle stack and static
hiding
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
50 Languages with abstract data type support, but not all features of object-orientation, sometimes called object-based languages. Examples: Modula-2 (with excellent encapsulation and information hiding), Pliant, CLU.
124 Component Objects - Utility and Implementation hiding objects
126 Impl. Hiding - Distr. Arch., specific DBMS, OS
228 [Booch 91, p. 45] defines: "Encapsulation is the process of hiding all of the
230 [Coad 91, 1.1.2] defines: "Encapsulation (Information Hiding). A principle,
2370 2. Implementation Hiding is not Compatible with Manual Memory Management
2371 Implementation hiding is a pillar of object-oriented programming,
implementations
1208 Short Answer: Parametric Polymorphism (although various implementations
1635 3.8.5) Implementations (Brief) (OMG
1708 Subject: ORB Implementations
1825 to use. That's why HP ORB Plus includes OMG interfaces and implementations
1966 agreement to align their implementations of CORBA. The two companies
2030 distributed implementations of C++ classes over
2095 Cooperative Framework implementations on supported platforms
2410 versions of garbage collection were merely crude implementations of
issues
518 the issues of shared bases and member conflict resolution. But most modern
616 encapsulation. These issues are orthogonal. Multiple-polymorphism implies
1100 the nested switch statement! [Martin 92] covers some of these issues.
1390 as well as basic OS i ssues such as memory, file, tasking management.
1596 Technology topics and issues. This publication features
2213 issues.
2400 multiple containers, leaving many memory management issues unaddressed.
2527 Klimas, Edward "Quality Assurance Issues for Smalltalk Based Applications",
lack
67 Steve Yegge and others noted that natural languages lack the OOP approach of strictly prioritizing things (objects
75 Christopher J. Date stated that critical comparison of OOP to other technologies, relational in particular, is difficult because of lack of an agreed-upon and rigorous definition of OOP. Date and Darwen propose a theoretical foundation on OOP that uses OOP as a kind of customizable type system to support RDBMS.
615 Multi-methods involve two primary concepts, multiple-polymorphism and lack of
617 more than one parameter can be used in the selection of a method. Lack of
1126 cases) to be available on formal objects and a lack of multiple-polymorphism
1394 on C++. [[ The lack of type-tests in C++ was a problem in other designs.]]
2313 One partial solution to a lack of GC is reference counting. In this
2366 objects, lack of polymorphism, and problems with interior pointers (e.g.
literature
18 A survey by Deborah J. Armstrong of nearly 40 years of computing literature identified a number of "quarks", or fundamental concepts, found in the strong majority of definitions of OOP.
426 may be an editable_item and a kind of literature.
685 literature, potentially providing a single static selection in many cases
1625 ftp! These are from the list of literature and periodicals listed in
2265 3.8.7) Books, Articles, And Literature (OMG
2598 Includes a survey of existing literature on testing of OO
2657 features for C++ testing. From the product literature:
2678 testing. Highlights from CenterLine literature:
1563 3.8.3) Mail Server Access (OMG
1567 Information via Mail Server:
1568 Send the following commands in a letter to the mail server.
1569 mail omg_server@omg.org
1577 list mail
1584 mail omg_server@omg.org
1589 list mail
2456 mail: Qualix Group
middleware
1694 (RDA), Remote Procedure Calls (RPC), Message-Oriented Middleware (MOM),
2131 middleware - run-time system software that is layered between an
2136 To do this effectively, middleware must be able to interpret the
2140 middleware achieves this, it makes enterprise computing a reality.
2141 As a result, middleware is quickly emerging as the best solution for
2142 overcoming system incompatibilities, and middleware such as
2148 The DOME Software System is comprehensive middleware that provides
2160 Calls (RPC), Message-Oriented Middleware (MOM), and Object Request
ml
975 schemes [Aho 85]. ML is prototypical in providing this facility.
1134 2.6) What Is This I Hear About ML And Functional Programming Languages? (Typing - Object-Oriented Technology)
1135 ML, Metalanguage, is a functional programming language with a strongly typed
1139 flexibility than dynamic typing and the same applies to ML (although see the
1140 appendixes for an experimental dynamic extension to ML, Alcool-90 and [Cardelli
1141 85] for a proper placement of ML's type system). ML doesn't use inheritance
1203 Functional languages such as ML, Russell, and Haskell provide a separation with
1233 languages. One such popular functional language is ML, in which all functions
o
1628 o I would like a one year subscription to First Class
1630 o I would like to order ______ copy(s) of the Object Management
1632 o I would like to order ______ copy(s) of the CORBA for $50 each.
1633 o [Combinations]
2162 o Open System
2167 o Standards Compliant
2188 o Object-Oriented Architecture
2214 o Support for Heterogeneous Environments
odmg
1337 Subject: ODMG Gopher and Web Addresses
1339 The Object Database Management Group (ODMG) has set up Gopher and Web
1341 Gopher: gopher.odmg.org, port 2073
1343 www.odmg.org:3083
1345 addresses and contact information for ODBMS vendors, ODMG membership
1350 ODMG, send an email message to info@odmg.org and you will receive an
1353 ODMG Executive Director
order
622 (messages) equivalent. Functional syntax was chosen "in order to minimize the
1548 In order to serve OMG membership interested in other object-oriented systems
1630 o I would like to order ______ copy(s) of the Object Management
1632 o I would like to order ______ copy(s) of the CORBA for $50 each.
2231 underlying vendor in order to process requests. From the user's
2302 5: In order to avoid problems 3 and 4, programmers may end up copying
2381 Manual memory management must make assumptions about a program's order of
2387 clear order of execution. Other dynam ic control structures, such as
original
49 Languages with most of the features of objects (classes, methods, inheritance, reusability), but in a distinctly original form. Examples: Oberon (Oberon-1 or Oberon-2) and Common Lisp.
278 Original Aristotlean classification defines a "class" as a generalization of
886 BETA a followup to Simula (by its original designers).
925 many different forms. Computer Science refers to Strachey's original
929 > Strachey's Original Definition [Strachey 67]:
1007 They refer to this as "best-fitting" types [Black 86]. The original Trellis
1199 [Raj 89], original trellis
2428 Smalltalk (in its original 1972 version) was initially intended to make
overriding
260 helping with abstract classes and overriding.
529 Overriding? (Object-Oriented Technology)
532 p56]. Overriding is the term used in Smalltalk and C++ for redefining a
537 is executed overriding the base class method, if any. Overriding in Simula
672 in many cases, such as requiring overriding methods to have identical
676 declared in a base class may have several functions overriding it in a derived
1068 which case the overriding function must be called. Statically determining all
perform
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
300 dictionaries for methods, instances, and parents and methods to perform all
355 perform inheritance this way, etc.). Because inheritance can be used to
356 perform differential changes, intercessory protocols allow users to not
597 can access the internal state of an object of that class to perform some
1913 to perform the same function.
2325 [Further, GC can perform compaction improving locality of reference.]
pointers
41 Attempts to find a consensus definition or theory behind objects have not proven very successful (however, see Abadi & Cardelli, A Theory of Objects[18] for formal definitions of many OOP concepts and constructs), and often diverge widely. For example, some definitions focus on mental activities, and some on program structuring. One of the simpler definitions is that OOP is the act of using "map" data structures or arrays that can contain functions and pointers to other maps, all with some syntactic and scoping sugar on top. Inheritance can be performed by cloning the maps (sometimes called "prototyping"). OBJECT:=>> Objects are the run time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle.
195 although vtables of function pointers for dynamic binding are an exception).
611 (e.g. C++ and Eiffel) is really in between (checked function pointers).
1072 vtables of function pointers in the actual objects (C++) or equivalent,
1074 function pointers with static typechecking in the base class, and filling them
1118 implemented with tables of function pointers and offsets), and is how
2366 objects, lack of polymorphism, and problems with interior pointers (e.g.
2379 and does not contain pointers.
provided
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
504 can be provided (and preferred); however, C++ provides both sliced and non-
921 provided by base classes or types (subclass and subtype polymorphism,
1038 functions using exactly the same interface - as is provided by virtual
1040 [The Author notes this is a functional view of polymorphism (as provided in
1061 typed subtype polymorphism, as provided in Emerald, can be implemented
1428 Summaries and comparisons will be provided in future FAQs. Suggestions for
2134 would have been provided by the application's native operating
rdom
1845 CORBA Implementation Descriptions: Iris RDOM
1849 Product: Isis Reliable Distributed Object Manager(tm) (RDOM)
1851 Isis RDOM(tm) is a fault tolerant distributed ORB platform for reliable
1852 multi-lingual object-oriented applications. RDOM provides an "object group"
1854 cooperating objects. RDOM is built on top of the Isis Distributed
1855 Toolkit(tm). RDOM provides interfaces from Smalltalk (Parcplace),
1856 Objective-C, and C++, and runs on most Unix workstations. RDOM is currently
1859 RDOM has been at beta test sites since January. General release of
recent
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
52 In recent years, object-oriented programming has become especially popular in dynamic programming languages. Python, Ruby and Groovy are dynamic languages built on OOP principles, while Perl and PHP have been adding object oriented features since Perl 5 and PHP 4, and ColdFusion since version 5.
205 term "Prototype" usually refers to prototype theory, a recent theory of
757 RD and represents a recent
872 found in [Jacobson 92], and along with recent business process "reengineering"
1132 also be found in recent versions of Eiffel.
1137 recent functional language and Haskell [Hudak 92] provides a more modern and
1190 behavior. [Liskov 93] provides a recent exposition.
scheme
147 pointer (such as void* in C++) and an embedded dynamic typing scheme are used
386 Objective-C, etc.), lisp-based (CLOS, Flavors, Scheme, etc.), and Pascal-based
396 definition, or both) can avoid confusion about which inheritance scheme is
661 scheme is used.
927 ad-hoc. Cardelli and Wegner followup with another classification scheme,
1129 A limited dynamic typing scheme, called RTTI (Run Time Type Identification),
2314 scheme each object keeps a count of references to it. When this count
2391 Because no memory management scheme is universal enough for all applications,
security
79 Richard Mansfield, author and former editor of COMPUTE! magazine, states that "like countless other intellectual fads over the years ("relevance", communism, "modernism", and so on—history is littered with them), OOP will be with us until eventually reality asserts itself. But considering how OOP currently pervades both universities and workplaces, OOP may well prove to be a durable delusion. Entire generations of indoctrinated programmers continue to march out of the academy, committed to OOP and nothing but OOP for the rest of their lives."[38] He also is quoted as saying "OOP is to writing a program, what going through airport security is to flying".
1909 - enhanced security;
1912 and network security; however, DOME does allow stream operators
1955 security systems providing for improved reliability of distributed systems
2139 security; and scale up to accommodate even the largest systems. When
2176 - Kerberos 5.4 (Security)
2202 - Kerberos 5.4 compatible security
2244 DOME, DOMEshell, DOME Security, DOME Data Manager, and DDM are
semantic
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
152 another semantic definition of OO using functions for methods and for
395 Defining inheritance (with a thorough description or denotational semantic
480 common in the AI domain, where semantic nets use inheritance to understand
519 systems support Multiple Inheritance by employing semantic resolution
1184 subtyping seems similar. A possible loss of semantic integrity
1189 This helps to insure the semantic integrity of replacing objects and their
share
99 concept applies", and "A concept is an idea or notion we share that applies
285 "A class is a set of objects that share a common structure and a common
388 inheritance can also share parents within a class lattice (CLOS and Eiffel
467 then a potential to share that class. Only one instance of the class will
762 D, and many others, also share common ground with SA and other existing
1170 This also insures all types share a common representation, or at least a
2164 customer's applications, making it possible to share information
2473 market pressure, to do so as well, or face market share erosion. Think
structures
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
41 Attempts to find a consensus definition or theory behind objects have not proven very successful (however, see Abadi & Cardelli, A Theory of Objects[18] for formal definitions of many OOP concepts and constructs), and often diverge widely. For example, some definitions focus on mental activities, and some on program structuring. One of the simpler definitions is that OOP is the act of using "map" data structures or arrays that can contain functions and pointers to other maps, all with some syntactic and scoping sugar on top. Inheritance can be performed by cloning the maps (sometimes called "prototyping"). OBJECT:=>> Objects are the run time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle.
726 operations, objects, and structures that commonly occur in software systems
2318 circular data structures. Two systems that use a reference count GC
2387 clear order of execution. Other dynam ic control structures, such as
2514 "Incremental Testing of Object-Oriented Class Structures",
suitesoftware
1691 > SUITESOFTWARE (SuiteDOME)
2120 CORBA Implementation Descriptions: SUITESOFTWARE (SuiteDOME)
2186 SUITESOFTWARE is a member of various standards groups and conforms
2243 ? 1995 SUITESOFTWARE
2245 trademarks of SUITESOFTWARE. All other products and product names are
2250 SUITESOFTWARE places particular emphasis on support and continuing
2253 to problems. SUITESOFTWARE `s support staff is available by
2263 platform. SUITESOFTWARE sales representatives are available to help
technologies
75 Christopher J. Date stated that critical comparison of OOP to other technologies, relational in particular, is difficult because of lack of an agreed-upon and rigorous definition of OOP. Date and Darwen propose a theoretical foundation on OOP that uses OOP as a kind of customizable type system to support RDBMS.
1675 > IONA Technologies, Dublin Orbix, info@iona.ie
1866 CORBA Implementation Descriptions: Object-Oriented Technologies DOME
1869 Object Oriented Technologies Ltd,
1931 Iona Technologies Ltd.
1973 Iona Technologies Ltd., fax: +353-1-6686573
2166 and its open platform structure accommodates future technologies.
2412 advanced as rapidly as most computer-related technologies and is now a robust,
terms
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
71 Responsibility-driven design defines classes in terms of a contract, that is, a class should be defined around a responsibility and the information that it shares. This is contrasted by Wirfs-Brock and Wilkerson with data-driven design, where classes are defined around the data-structures that must be held. The authors hold that responsibility-driven design is preferable.
85 similar objects are defined in their common class; the terms instance and
151 It is primarily intended to introduce new terms. See [Cardelli 85] for
177 The terms method
363 systems, which often refer to systems implemented in terms of themselves, or
594 Behavior is how an object acts and reacts, in terms of its state changes
744 respectively. OOA strives to understand and model, in terms of object-oriented
versions
54 ECMAScript language. JavaScript is perhaps the best known prototype- based programming language, which employs cloning from prototypes rather than inheriting from a class. Another scripting language that takes this approach is Lua. Earlier versions of ActionScript (a partial superset of the ECMA-262 R3, otherwise known as ECMAScript) also used a prototype-based object model. Later versions of ActionScript incorporate a combination of classification and prototype-based object models based largely on the currently incomplete ECMA-262 R4 specification, which has its roots in an early JavaScript 2 Proposal. Microsoft's JScript.NET also includes a mash-up of object models based on the same proposal, and is also a superset of the ECMA-262 R3 specification.
1132 also be found in recent versions of Eiffel.
1683 1 versions of ORBeline available; will
1961 out versions of Orbix for Microsoft Windows NT, Silicon Graphics IRIX and
2258 execute DOME plus PostScriptTM versions of DOME documentation.
2259 Hardcopy versions of all DOME documentation are available for a
2410 versions of garbage collection were merely crude implementations of
wirfs-brock
71 Responsibility-driven design defines classes in terms of a contract, that is, a class should be defined around a responsibility and the information that it shares. This is contrasted by Wirfs-Brock and Wilkerson with data-driven design, where classes are defined around the data-structures that must be held. The authors hold that responsibility-driven design is preferable.
764 models, and even DFD's. Booch, Jacobson, and Wirfs-Brock are examples of OO
1420 Wirfs-Brock et al. [Wirfs-Brock 90]
1445 Booch OOD, Wirfs-Brock responsibility-driven design.
1465 [Wilkie 93] summarizes, compares, and provides examples of Booch, Wirfs-Brock,
1468 Wirfs-Brock, R.J. and Johnson, R.E., "Surveying Current Research in Object-
1485 Wirfs-Brock, R. et.al. - Designing object-oriented software, 1990.
ac
2529 email address is "ac690@cleveland.freenet.edu".
2578 available by anonymous ftp from vega.dur.ac.uk as
2601 This paper is available by anonymous ftp from vega.dur.ac.uk in
2613 This paper is available by anonymous ftp from vega.dur.ac.uk in
2624 This paper is available by anonymous ftp from vega.dur.ac.uk in
2635 This paper is available by anonymous ftp from vega.dur.ac.uk in
2703 The software is available via anonymous FTP from bright.ecs.soton.ac.uk
anonymous
2335 anonymous ftp (cs.utexas.edu:pub
2578 available by anonymous ftp from vega.dur.ac.uk as
2601 This paper is available by anonymous ftp from vega.dur.ac.uk in
2613 This paper is available by anonymous ftp from vega.dur.ac.uk in
2624 This paper is available by anonymous ftp from vega.dur.ac.uk in
2635 This paper is available by anonymous ftp from vega.dur.ac.uk in
2703 The software is available via anonymous FTP from bright.ecs.soton.ac.uk
basis
11 The Smalltalk language, which was developed at Xerox PARC (by Alan Kay and others) in the 1970s, introduced the term object-oriented programming to represent the pervasive use of objects and messages as the basis for computation. Smalltalk creators were influenced by the ideas introduced in Simula 67, but Smalltalk was designed to be a fully dynamic system in which classes could be created and modified dynamically rather than statically as in Simula 67.[9] Smalltalk and with it OOP were introduced to a wider audience by the August 1981 issue of Byte Magazine.
40 records are basis for understanding objects if function literals can be stored in fields (like in functional programming languages), but the actual calculi need be considerably more complex to incorporate essential features of OOP. Several extensions of System F<: that deal with mutable objects have been studied;[18] these allow both subtype polymorphism and parametric polymorphism (generics)
742 interact on a fairly frequent basis with the domain analysis effort.
842 Level 4: Managed: A measurable basis for all improvements to the process.
1270 basis.
1536 Adopted specifications are available on a fee-free basis to members and
2475 was choosing a basis for the next five years of work, wouldn't you feel
berard
724 [The following quotes on domain analysis are from [Berard 93]]
794 an overall system perspective and [Berard 93] proposes an (incremental)
1399 Berard [Berard 93]
2479 Berard, Edward. Essays on Object-Oriented Software Engineering.
2483 Berard, Edward. Project Management Handbook. Must be purchased
2484 direct from Berard Software Engineering, Ltd., 902 Wind River
building
1713 Its a toolkit for building failure resilient, distributed applications
1738 SUBJECT: HP INTRODUCES DISTRIBUTED-COMPUTING SOLUTION FOR BUILDING
1742 today introduced a distributed-computing solution for building scalable,
1788 heterogeneous support for building, managing and using distributed object-
2024 for building computing applications and services on networks
2046 - building next-generation, object-oriented,
2699 A group of volunteers is building a C++ test harness for the automated
comp
691 point often mistaken in comp.object. E.g. simple statically
1279 Java (comp.lang.java, http:
1313 See also Appendices B and E and the comp.database.object newsgroup.
2436 Posted to comp.object, comp.lang.c++, comp.lang.smalltalk and
2437 comp.software.testing.
compiler
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
70 OOP was developed to increase the reusability and maintainability of source code. Transparent representation of the control flow had no priority and was meant to be handled by a compiler. With the increasing relevance of parallel hardware and multithreaded coding, developer transparent control flow becomes more important, something hard to achieve with OOP.
315 programs (no Meta-Class except for in the compiler and perhaps for type-safe
360 of object-oriented reuse, since the compiler itself is reused thru
1820 language compiler, static and dynamic invocation interface and interface
1980 Operating System C++ Compiler Release
2467 also be testable under different OS configurations, different compiler
computers
371 of the real world. See the example below using computers.
486 in Personal computers are also available to all of its subclasses. This kind
1395 ETHOS was implemented as an operating system for the Ceres computers
1806 also will run on Apple Macintosh computers and on any PC running the Windows
2025 of heterogeneous computers.
2045 computers, operating systems and networks
2048 networks of heterogeneous computers, operating
covers
110 covers "Identifying Key Abstractions" for objects and classes based on an
168 [Stroustrup 90] covers the implementation details of virtual member functions
1011 [As inclusion polymorphism covers both subtype and subclass polymorphism,
1100 the nested switch statement! [Martin 92] covers some of these issues.
1386 This thesis covers the design of an extensible object-oriented
1391 It covers extensible objected-oriented programming from hardware up.
2275 [Covers CORBA standards with respect to OODBs]
created
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
11 The Smalltalk language, which was developed at Xerox PARC (by Alan Kay and others) in the 1970s, introduced the term object-oriented programming to represent the pervasive use of objects and messages as the basis for computation. Smalltalk creators were influenced by the ideas introduced in Simula 67, but Smalltalk was designed to be a fully dynamic system in which classes could be created and modified dynamically rather than statically as in Simula 67.[9] Smalltalk and with it OOP were introduced to a wider audience by the August 1981 issue of Byte Magazine.
45 Simula (1967) is generally accepted as the first language to have the primary features of an object-oriented language. It was created for making simulation programs, in which what came to be called objects were the most important information representation. Smalltalk (1972 to 1980) is arguably the canonical example, and the one with which much of the theory of object-oriented programming was developed. Concerning the degree of object orientation, following distinction can be made:
207 prototype for newly created instances. [The Author also uses the term for
427 Mixin's is a style of MI (from flavors) where a class is created to provide
493 close to what's required; a derived class can be created to specialize it.
customers
1748 overall distributed-computing strategy, which is designed to give customers
1751 HP believes it is best positioned to help customers take advantage of
1753 products, understands how to help customers adopt new technology for maximum
1779 have made it easier for their customers to port applications between their
1861 The C++ interface in August. Customers include AMD, Consilium and Swiss
2032 - allows customers to build and use object services
2254 telephone, FAX, and e-mail to help customers maximize the use of the
date
75 Christopher J. Date stated that critical comparison of OOP to other technologies, relational in particular, is difficult because of lack of an agreed-upon and rigorous definition of OOP. Date and Darwen propose a theoretical foundation on OOP that uses OOP as a kind of customizable type system to support RDBMS.
1338 Date: 24 Oct 1994 13:10:02 -0400
1709 Date: Tue, 4 May 1993 13:12:36 +0200 (MET DST)
1740 DATE: September 27, 1993
1981 Date
2090 Release date - Release 3.0 is available now to early
dce
1756 HP ORB PLUS: CORBA AND DCE COMBINED
1758 specification from the Object Management Group with the DCE standard from
1759 the Open Software Foundation(tm) as its transport mechanism. DCE is
1761 without modification -- on any other system that supports DCE. HP ORB Plus
1766 The DCE (Distributed Computing Environment) standard provides an
1777 DCE standard. This object- enabling technology specification was jointly
1847 Subject: Re: DCE vs. CORBA
describes
57 Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1995 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, sometimes casually called the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. As of April 2007, the book was in its 36th printing.
58 The book describes the following patterns:
2340 Sept 1988. This describes GC in C and C++.
2520 are dhoffman@csr.uvic.ca and pstropp@cs.uq.oz.au. Describes an
2575 Describes ways in which the usual approach to software testing
2590 important for OOP and describes one quality program.
2610 England. Describes a series of tools for the generation and
develop
1545 develop nor sell software of any kind. Instead, it selects and promulgates
1744 With HP ORB Plus, programmers can develop scalable, object-based
1794 We plan to use HP ORB Plus to develop new object-based products that
1922 you to easily develop large distributed applications that are robust,
1940 Architecture (CORBA) standard. With Orbix, programmers can develop
2151 develop applications on any platform they choose and then easily
2422 are generally more reliable and easier to develop, maintain, and reuse than
durham
2596 Engineering and Computer Sciences (SECS), University of Durham,
2609 Computer Science (SECS), University of Durham, Durham,
2621 University of Durham, Durham, England. Discusses different
2631 Engineering and Computer Science (SECS), University of Durham,
2632 Durham, England.
efficiency
645 used in languages with static typing for simplicity and efficiency
659 doesn't support multiple-polymorphism and either efficiency considerations
671 efficiency, and to support a static programming idiom, but require restrictions
682 There is some concern about the efficiency of run-time method selection as
1089 Again, various optimizations exist for dynamic lookup to increase efficiency
1163 efficiency by taking advantage of that representation wherever used. In many
1228 efficiency tradeoff), and sources can cause inlining and create source code
electra
1699 The ELECTRA Toolkit (not finished)
1703 CORBA Implementation Descriptions: The ELECTRA Toolkit
1707 The ELECTRA Toolkit
1712 Electra is a research project and not available yet.
1715 etc. Electra is based on the HORUS toolkit (which is "the new ISIS
1717 An overview paper to electra is available from:
1720 electra.ps.Z
emerald
46 Languages called "pure" OO languages, because everything in them is treated consistently as an object, from primitives such as characters and punctuation, all the way up to whole classes, prototypes, blocks, modules, etc. They were designed specifically to facilitate, even enforce, OO methods. Examples: Scala, Smalltalk, Eiffel, JADE, Emerald.
1001 is-a-member-of form in OO). Emerald provides another example of an object-
1061 typed subtype polymorphism, as provided in Emerald, can be implemented
1179 this issue in Emerald. The same issue arises in parametric polymorphism
1197 The formal type system found in [Cardelli 85], Emerald
1259 There are many alternatives in OO. Emerald
1277 Emerald
emphasis
747 expert's perspective and with an emphasis on modeling the real-world (the
766 "structured" techniques, with greater emphasis on objects. OOram [Reenskaug
767 91] provides support and emphasis on types and roles as guiding principles,
843 Level 5: Optimizing: Emphasis on defect prevention and optimizing
889 Reuse, quality, an emphasis on modeling the real world (or a "stronger
1246 list instead of a parent list. Thus, delegation's primary emphasis is
2250 SUITESOFTWARE places particular emphasis on support and continuing
event
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
1826 for properties, life cycle, associations, event notification and naming.
2071 - Event Service (Release 3.1) - Implements an OMG
2073 compliant event service
2200 - Concern registration and event notification
2386 of an object. For example, event driven GUI programs frequently have no
fax
1499 Feel free to call, fax or email for more information.
1871 Telephone: +44 (0) 1926 833488 Fax: +44 (0) 1926 883370.
1973 Iona Technologies Ltd., fax: +353-1-6686573
2105 FAX
2254 telephone, FAX, and e-mail to help customers maximize the use of the
2453 fax: 415
2674 (0225) 444400 (FAX)
fields
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
40 records are basis for understanding objects if function literals can be stored in fields (like in functional programming languages), but the actual calculi need be considerably more complex to incorporate essential features of OOP. Several extensions of System F<: that deal with mutable objects have been studied;[18] these allow both subtype polymorphism and parametric polymorphism (generics)
156 whose record fields are called instance variables (Smalltalk) or member data
192 Objects contain fields, methods and delegates (pseudo parents), whereas
200 fields, methods and parents and any object can be used as a template
1251 inheritance" in which fields and methods can be added and deleted from objects.
formatting
2604 US letter paper formatting.
2615 papers. Get "tools.ps.Z" for A4 paper formatting or get
2616 "toolsus.ps.Z" for US letter formatting.
2626 papers. Get "guide.ps.Z" for A4 paper formatting or get
2627 "guideus.ps.Z" for US letter formatting.
2637 papers. Get toopinht.ps.Z" for A4 paper formatting or get
2638 "toopinhtus.ps.Z" for US letter formatting.
foundation
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
75 Christopher J. Date stated that critical comparison of OOP to other technologies, relational in particular, is difficult because of lack of an agreed-upon and rigorous definition of OOP. Date and Darwen propose a theoretical foundation on OOP that uses OOP as a kind of customizable type system to support RDBMS.
1677 > NCR 'Cooperative Frameworks' -- a Distributed Object Foundation
1759 the Open Software Foundation(tm) as its transport mechanism. DCE is
2008 CORBA Implementation Descriptions: NCR 'Cooperative Frameworks' -- a Distributed Object Foundation
2014 a Distributed Object Foundation
2023 Cooperative Frameworks is a distributed object foundation
future
1314 Refs to be included in future FAQs.
1347 ODMG-93 along with ODL lex and yacc files. In the future, we will be
1355 Refs to be included in future FAQs. See also Appendix E.
1428 Summaries and comparisons will be provided in future FAQs. Suggestions for
2038 toolkits (others are planned for future release) --
2166 and its open platform structure accommodates future technologies.
2269 This section is expected to grow considerably in the future.
greater
491 testing providing even greater reliability.
765 methodologies representing a greater departure from the conventional
766 "structured" techniques, with greater emphasis on objects. OOram [Reenskaug
829 From a greater perspective, the SEI has developed the Capability Maturity Model
1164 OO languages, subclassing and dynamic binding provides for greater flexibility
1178 signatures can occur, calling for greater care in use. [Black 86] discusses
1186 contrasted with greater power.
hardware
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
12 In the 1970s, Kay's Smalltalk work had influenced the Lisp community to incorporate object- based techniques that were introduced to developers via the Lisp machine. Experimentation with various extensions to Lisp (like LOOPS and Flavors introducing multiple inheritance and mixins), eventually led to the Common Lisp Object System (CLOS, a part of the first standardized object-oriented programming language, ANSI Common Lisp), which integrates functional programming and object-oriented programming and allows extension via a Meta- object protocol. In the 1980s, there were a few attempts to design processor architectures that included hardware support for objects in memory but these were not successful. Examples include the Intel iAPX 432 and the Linn Smart Rekursiv.
66 However, Niklaus Wirth (who popularized the adage now known as Wirth's law: "Software is getting slower more rapidly than hardware becomes faster") said of OOP in his paper, "Good Ideas through the Looking Glass", "This paradigm closely reflects the structure of systems 'in the real world', and it is therefore well suited to model complex systems with complex behaviours" (contrast KISS principle).
70 OOP was developed to increase the reusability and maintainability of source code. Transparent representation of the control flow had no priority and was meant to be handled by a compiler. With the increasing relevance of parallel hardware and multithreaded coding, developer transparent control flow becomes more important, something hard to achieve with OOP.
1391 It covers extensible objected-oriented programming from hardware up.
1607 of developers, operating systems and hardware; and enhance long-
2126 updating a collection of incompatible hardware platforms, operating
hierarchy
226 Self is a good example of a delegation-based single hierarchy language
439 distinct parents can declare a member within a multiple inheritance hierarchy,
459 Smalltalk provide dynamic inheritance in some form or other. Single hierarchy
524 hierarchy "creation" mechanism, however this loses polymorphism and loses the
574 Hierarchy (Inheritance)
589 hybrid systems). However, all objects may be classes in single hierarchy
1328 viewed as a hierarchy, with locals
incremental
790 incremental, iterative, evolutionary, concurrent and situational nature of
792 with a risk-driven incremental prototyping approach. [Booch 91, 6.1]
794 an overall system perspective and [Berard 93] proposes an (incremental)
812 [Author's note: The spiral model is often incremental and may waterfall if
2514 "Incremental Testing of Object-Oriented Class Structures",
2535 dependencies. This in-turn permits incremental,
2634 particularily incremental testing.
integration
1606 encourages reuse of code; allows useful integration across lines
1782 System Object Model with extensions for distribution. This integration will
1893 integration for legacy systems.
1969 In addition Orbix-TP, integration with Tuxedo for transaction processing, has
1970 just entered beta testing. Work is underway on Orbix-FT, integration with
2664 testing, unit testing and integration testing. Cantata has been
2687 *Integration with leading programming tools for maximum productivity gains
interoperability
1616 requests and receive responses. The ORB provides interoperability
1784 interoperability of distributed applications across HP and IBM platforms.
1831 interoperability is planned so objects written in different languages can be
1967 demonstrated interoperability between IONA's Orbix running on Microsoft
2094 Product interoperability - Full interoperability between NCR
2096 is available now; interoperability with selected CORBA 1.1
isis
1715 etc. Electra is based on the HORUS toolkit (which is "the new ISIS
1848 Reply-To: rcbc@isis.com
1849 Product: Isis Reliable Distributed Object Manager(tm) (RDOM)
1850 Company: Isis Distributed Systems, Inc., Ithaca NY, USA.
1851 Isis RDOM(tm) is a fault tolerant distributed ORB platform for reliable
1854 cooperating objects. RDOM is built on top of the Isis Distributed
1971 the Isis distributed system, will deliver a fault-tolerant ORB.
kinds
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
7 Objects can be thought of as wrapping their data within a set of functions designed to ensure that the data are used appropriately, and to assist in that use. The object's methods will typically include checks and safeguards that are specific to the types of data the object contains. An object can also offer simple-to-use, standardized methods for performing particular operations on its data, while concealing the specifics of how those tasks are accomplished. In this way alterations can be made to the internal structure or methods of an object without requiring that the rest of the program be modified. This approach can also be used to offer standardized methods across different types of objects. As an example, several different types of objects might offer print methods. Each type of object might implement that print method in a different way, reflecting the different kinds of data each contains, but all the different print methods might be called in the same standardized manner from elsewhere in the program. These features become especially useful when more than one programmer is contributing code to a project or when the goal is to reuse code between projects.
317 There are 2 kinds of distinct objects: objects and classes.
324 There are 2 kinds of distinct objects (objects and classes), with a
339 C++). There are 3 distinct kinds of objects (objects, classes, and
367 Inheritance provides a natural classification for kinds of objects and allows
1084 many kinds of objects such as text and graphical objects, multiple-polymorphism
machine
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
12 In the 1970s, Kay's Smalltalk work had influenced the Lisp community to incorporate object- based techniques that were introduced to developers via the Lisp machine. Experimentation with various extensions to Lisp (like LOOPS and Flavors introducing multiple inheritance and mixins), eventually led to the Common Lisp Object System (CLOS, a part of the first standardized object-oriented programming language, ANSI Common Lisp), which integrates functional programming and object-oriented programming and allows extension via a Meta- object protocol. In the 1980s, there were a few attempts to design processor architectures that included hardware support for objects in memory but these were not successful. Examples include the Intel iAPX 432 and the Linn Smart Rekursiv.
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
73 Luca Cardelli wrote a paper titled "Bad Engineering Properties of Object-Oriented Languages" Richard Stallman wrote in 1995, "Adding OOP to Emacs is not clearly an improvement; I used OOP when working on the Lisp Machine window systems, and I disagree with the usual view that it is a superior way to program."
1357 all the way down to to the machine (OO architectures are found at the bottom).
1891 be built and tested on a single machine using local resources.
2233 its entirety on the local machine. This is possible because DDM maps
manager
1849 Product: Isis Reliable Distributed Object Manager(tm) (RDOM)
2035 IP, NetBIOS, Lan Manager NetBEUI and
2108 Randy Volters, Sr. Product Manager
2221 DOME Data Manager (DDMTM) database access manager.
2223 The DOME Data Manager is a complete relational DBMS engine that
2244 DOME, DOMEshell, DOME Security, DOME Data Manager, and DDM are
manual
2322 unacceptable in some applications. However the overhead of manual
2355 1. Manual Memory Management Breaks Encapsulation.
2370 2. Implementation Hiding is not Compatible with Manual Memory Management
2381 Manual memory management must make assumptions about a program's order of
2408 It is not enough to merely find fault with manual memory management. One also
2420 superior real-time performance as manual management usually has difficulty
2424 manual management to provide the programmer with the broadest set of tools,
meta-classes
299 picture Meta-Classes. Classes must be implemented in some way; perhaps with
310 objects (as in Self). There is no need for Meta-Classes because objects
328 of specialized Meta-Classes for classes. There is still a Meta-Class as in
333 class class (Smalltalk's Meta-Classes)
350 Meta-Classes accessible to users [Kiczales 92, Paepcke 93]. In CLOS
583 meta-classes. But classes play a dual role, because objects can only be
1242 This is the 1 Level System as Described under Meta-Classes. Delegation refers
multi-methods
22 Encapsulation (or multi-methods, in which case the state is kept separate)
614 What Are Multi-Methods And Multiple-Polymorphism? (Object-Oriented Technology)
615 Multi-methods involve two primary concepts, multiple-polymorphism and lack of
619 packages can be used to restrict access, as in CLOS). Multi-methods can also
624 [Chambers 93] discusses multi-methods in his new OO language, Cecil.
662 Why do multi-methods allow open access to parameters? It allows efficient
693 multi-methods still require dynamic types!]
natural
67 Steve Yegge and others noted that natural languages lack the OOP approach of strictly prioritizing things (objects
198 or shared state, otherwise idiosyncratic objects, a powerful and natural
367 Inheritance provides a natural classification for kinds of objects and allows
369 and constructing object systems. Natural means we use concepts,
478 Inheritance is a natural way to model the world or a domain of discourse,
479 and so provides a natural model for OOA and OOD (and even OOP). This is
2430 objects was something more intuitive and natural than coding procedures.
object's
7 Objects can be thought of as wrapping their data within a set of functions designed to ensure that the data are used appropriately, and to assist in that use. The object's methods will typically include checks and safeguards that are specific to the types of data the object contains. An object can also offer simple-to-use, standardized methods for performing particular operations on its data, while concealing the specifics of how those tasks are accomplished. In this way alterations can be made to the internal structure or methods of an object without requiring that the rest of the program be modified. This approach can also be used to offer standardized methods across different types of objects. As an example, several different types of objects might offer print methods. Each type of object might implement that print method in a different way, reflecting the different kinds of data each contains, but all the different print methods might be called in the same standardized manner from elsewhere in the program. These features become especially useful when more than one programmer is contributing code to a project or when the goal is to reuse code between projects.
33 Decoupling refers to careful controls that separate code modules from particular use cases, which increases code re-usability. A common use of decoupling in OOP is to polymorphically decouple the encapsulation (see Bridge pattern and Adapter pattern) - for example, using a method interface which an encapsulated object must satisfy, as opposed to using the object's class.
352 what is this object's class, give info on this class, etc.) and an
501 class. Such assignment can result in the loss of an object's dynamic type in
502 favor of a static type (or even loss of an object's representation to that of
1109 that object must be a member of the polymorphic object's class.
1167 (transitively) from any polymorphic object's class (inclusion polymorphism
operation
598 operation. It can be thought of as a procedure with the first parameter as
1045 "Polymorphism" means that the same operation may behave differently on
1081 multiple-polymorphism, a cut operation in an Edit submenu may pass the cut
1082 operation (along with parameters) to any object on the desktop, each of which
1094 as each object knows what operation to support. It also allows a reduction in
2075 directory entries required for cross domain operation
2660 operation. Cantata is suitable for testing software written in
paradigm
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
66 However, Niklaus Wirth (who popularized the adage now known as Wirth's law: "Software is getting slower more rapidly than hardware becomes faster") said of OOP in his paper, "Good Ideas through the Looking Glass", "This paradigm closely reflects the structure of systems 'in the real world', and it is therefore well suited to model complex systems with complex behaviours" (contrast KISS principle).
1236 3.1) What Is The "Classical" Object-Oriented Paradigm?
1240 Prototyping" Object-Oriented Paradigm?
1853 paradigm for constructing complex applications out of collections of
2384 oriented paradigm of objects sending messages to each other (possibly from
paul
77 Paul Graham has suggested that the purpose of OOP is to act as a "herding mechanism" that keeps mediocre programmers in mediocre organizations from "doing too much damage". This is at the expense of slowing down productive programmers who know how to use more powerful and more compact techniques.
1972 Paul Hickey, tel: +353-1-6686522
2278 written for the FAQ by Paul Johnson and the second is from the FAQ author's
2281 From: Paul Johnson (paj@gec-mrc.co.uk)
2329 [2] "Uniprocessor Garbage Collection Techniques," by Paul R. Wilson,
2517 Hoffman, Daniel and Paul Strooper. A Case Study in Class Testing.
2691 contact Paul Townsend, townsend@mprgate.mpr.ca.
performance
716 operational characteristics (e.g. reliability, availability, performance)".
1812 -- up to 400 percent increased performance, through quicker
1885 ORBs and servers. It is a multi-threaded high performance ORB
1911 - dynamic invocation, which is seen as detrimental to performance
2364 performance than GC, awkward syntax, and poor semantics, which typically
2402 sharing and carrying expensive performance costs when complex objects are
2420 superior real-time performance as manual management usually has difficulty
powerful
77 Paul Graham has suggested that the purpose of OOP is to act as a "herding mechanism" that keeps mediocre programmers in mediocre organizations from "doing too much damage". This is at the expense of slowing down productive programmers who know how to use more powerful and more compact techniques.
135 based approaches (e.g. Smalltalk handles) allow powerful dynamic typing, as
198 or shared state, otherwise idiosyncratic objects, a powerful and natural
225 1 level systems therefore provide the most flexible and powerful capabilities.
768 which is quite powerful. [Booch 94] presents a methodology which is an
884 powerful dynamic typing mechanism (although these existed to some extent in
903 Polymorphism is often considered the most powerful facility of an OOPL.
procedural
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
17 Just as procedural programming led to refinements of techniques such as structured programming, modern object-oriented software design methods include refinements[citation needed] such as the use of design patterns, design by contract, and modeling languages (such as UML).
47 Languages designed mainly for OO programming, but with some procedural elements. Examples: C++, C#, VB.NET, Java, Python.
48 Languages that are historically procedural languages, but have been extended with some OO features. Examples: Visual Basic (derived from BASIC), Fortran 2003, Perl, COBOL 2002, PHP, ABAP.
69 verbs).] This problem may cause OOP to suffer more convoluted solutions than procedural programming.
74 A study by Potok has shown no significant difference in productivity between OOP and procedural approaches.
2383 object. While this is often possible in procedural languages, the object-
programmer
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
7 Objects can be thought of as wrapping their data within a set of functions designed to ensure that the data are used appropriately, and to assist in that use. The object's methods will typically include checks and safeguards that are specific to the types of data the object contains. An object can also offer simple-to-use, standardized methods for performing particular operations on its data, while concealing the specifics of how those tasks are accomplished. In this way alterations can be made to the internal structure or methods of an object without requiring that the rest of the program be modified. This approach can also be used to offer standardized methods across different types of objects. As an example, several different types of objects might offer print methods. Each type of object might implement that print method in a different way, reflecting the different kinds of data each contains, but all the different print methods might be called in the same standardized manner from elsewhere in the program. These features become especially useful when more than one programmer is contributing code to a project or when the goal is to reuse code between projects.
2293 storage cannot be made by the programmer. Drawing editors and
2295 programmer has to write an application-specific garbage collector.
2424 manual management to provide the programmer with the broadest set of tools,
2466 testable during initial evaluation by the client programmer. They must
pure
46 Languages called "pure" OO languages, because everything in them is treated consistently as an object, from primitives such as characters and punctuation, all the way up to whole classes, prototypes, blocks, modules, etc. They were designed specifically to facilitate, even enforce, OO methods. Examples: Scala, Smalltalk, Eiffel, JADE, Emerald.
215 search for an attribute to a delegate, and is therefore more of a pure
1058 for the polymorphic object; and hence, polymorphism. This common pure
1060 subclass polymorphism to be more specific (see section 2.1). Pure statically
1138 "pure" example. Section 2.5 discusses why static typing has less power
1144 "pure" statically (or strongly) checked parametric polymorphism, by Strachey's
1204 pure parametric polymorphism (as is also commonly found in OO languages in
record
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
155 expanded types in Eiffel) can be viewed as instances of a record type,
156 whose record fields are called instance variables (Smalltalk) or member data
157 (C++). The record (class) may also contain operations which are called
159 function taking an object of the record type, called the receiver, as the
162 roughly equivalent to a loosely coupled variant record, with derived classes
970 "Subtyping on record types corresponds to the concept of inheritance
referred
191 only objects, they are referred to as single-hierarchy, or 1 Level systems.
561 programming often referred to as "object based"", which is quite different
609 If done statically, this can be referred to as invocation, and message passing
815 the process is often referred to as seamless, meaning there is no conceptual
882 referred to as simply Simula. Smalltalk was the next major contributor
935 Parametric polymorphism is also referred to as "true" polymorphism, whereas
965 Parametric polymorphism is referred to as generics. Generics can be syntactic,
related
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
940 divided into parametric and inclusion polymorphism, which are closely related,
963 related, but are distinct enough in implementation to justify separate
1017 related by some common superclass; thus, any object denoted by this name is
1154 in OO. Parametric polymorphism is a related concept where this is also true,
1348 adding more links to related sites, bibliographies, and a FAQ for ODBMSs.
1798 In a related announcement, HP introduced Version 2.0 of HP Distributed
relationship
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
372 Inheritance is a relationship between classes where one class is the parent
378 [LaLonde 90]) and can be used as an is-a-kind-of (or is-a) relationship or
404 An example of the is-a-kind-of relationship is shown below. Is-a is often
406 instantiation relationship. In classical OO, inheritance is a relationship
487 of reuse takes advantage of the is-a-kind-of relationship. Class libraries
require
671 efficiency, and to support a static programming idiom, but require restrictions
693 multi-methods still require dynamic types!]
992 require explicit instantiation of its template functions, formal generic
1192 similar to subtype polymorphism; however, ACs require type compatible classes
1822 writing distributed, object-oriented applications require additional
2183 beyond what many of the standards require, it makes the task of
2284 OO Languages which require garbage collection include Eiffel, Smalltalk and
requires
385 don't specify new state by default (to do so requires cloning), C-based (C++,
476 resolution but requires more work for parents with many features.
678 requires both static and dynamic typing, because no formal argument
709 requires."
1155 but is of a different flavor (and usually requires object attributes by use.
2353 There are several reasons why true object-oriented programming requires garbage
2372 but explicit memory management requires implementation-dependent
role
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
87 defined in [Coplien 92, p280], where "classes play a central role in the
94 unit, or entity, either real or abstract, with a well-defined role in the
189 flexible kind of object which can play the role of classes in classical OO
196 However, one-le vel objects often play the role of classes to take advantage of
202 thus performing the classical role of a class. In typical prototyping systems,
583 meta-classes. But classes play a dual role, because objects can only be
shlaer
102 the problem at hand." [Shlaer 88, p 14] defines: "An object is an abstraction
753 [Shlaer 88] is often credited as the first book on OOA, although their method
755 and Constantine. Their complete approach ([Shlaer 88, 92]) consists of
1417 Shlaer and Mellor [Shlaer 88 and 92]
1466 Hood, Coad and Yourdon, Winter Partners, Shlaer and Mellor, Jacobson,
1483 Shlaer, S., Mellor, S.J. - Object-oriented systems analysis: Modeling the
solution
55 Challenges of object-oriented design are addressed by several methodologies. Most common is known as the design patterns codified by Gamma et al.. More broadly, the term "design patterns" can be used to refer to any general, repeatable solution to a commonly occurring problem in software design. Some of these commonly occurring problems have implications and solutions particular to object-oriented development.
63 Both object-oriented programming and relational database management systems (RDBMSs) are extremely common in software today. Since relational databases don't store objects directly (though some RDBMSs have object-oriented features to approximate this), there is a general need to bridge the two worlds. The problem of bridging object-oriented programming accesses and data patterns with relational databases is known as Object-Relational impedance mismatch. There are a number of approaches to cope with this problem, but no general solution without downsides.[20] One of the most common approaches is object-relational mapping, as found in libraries like Java Data Objects and Ruby on Rails' ActiveRecord.
1738 SUBJECT: HP INTRODUCES DISTRIBUTED-COMPUTING SOLUTION FOR BUILDING
1742 today introduced a distributed-computing solution for building scalable,
2141 As a result, middleware is quickly emerging as the best solution for
2165 between new and legacy applications. DOME provides a solution today
2313 One partial solution to a lack of GC is reference counting. In this
special
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
25 Open recursion – a special variable (syntactically it may be a keyword), usually called this or self, that allows a method body to invoke another method body of the same object. This variable is late-bound; it allows a method defined in one class to invoke another method that is defined later, in some subclass thereof.
917 object-oriented polymorphism. This is a special case of parametric
1231 special case of type variables.
1549 arenas besides the distributed system problem, the Group supports Special
2552 simply a special case of testing software which retains state
2656 testing C++, but as far as I am able to determine, it has no special
st
1870 1st Floor, Lawrence House, 1A Morrell St, Leamington Spa, England CV32 5SZ
2331 Management, Sept. 1992, St. Malo, France, Yves Bekkers and Jacques Cohen,
2457 1900 S. Norfolk St., #224
2653 st80_vw
2654 TreeLW1.1" from st.cs.uiuc.edu.
2692 Software Research Inc. (625 Third St, San Francisco, CA 94107-1997,
stack
1216 programming languages. An example is a Stack with a generically
1217 parameterized base type. This allows a single Stack class to provide
1218 many instantiations such as a Stack of ints, a Stack of any fundamental
1219 or user defined type, or even a Stack of Stacks of ... Another example is
2311 length, include file nesting and macro stack depth. This causes
2365 include failure to reclaim cycles, inability to handle stack and static
structured
17 Just as procedural programming led to refinements of techniques such as structured programming, modern object-oriented software design methods include refinements[citation needed] such as the use of design patterns, design by contract, and modeling languages (such as UML).
754 adds OO techniques to the traditional structured analysis principles of Yourdon
758 addition to the structured analysis family (as does Martin and Odell).
766 "structured" techniques, with greater emphasis on objects. OOram [Reenskaug
818 programming gaps found in traditional structured analysis and design.
1317 structured subobjects, each object has its own identity, or object-id (as
2373 low-level knowledge of how memory is structured. For example, programmers
subject
106 * all instances are subject to and conform to the same rules"
1337 Subject: ODMG Gopher and Web Addresses
1585 Subject:
1708 Subject: ORB Implementations
1738 SUBJECT: HP INTRODUCES DISTRIBUTED-COMPUTING SOLUTION FOR BUILDING
1847 Subject: Re: DCE vs. CORBA
2010 Subject: re-post: NCR Cooperative Frameworks (new phone no.)
superclass
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
374 superclass
981 insta nce of a superclass is required. For subtyping (subtype polymorphism),
1017 related by some common superclass; thus, any object denoted by this name is
2644 (bruce@utafll.uta.edu). It is a general superclass for application
switch
171 switch statement on variant parts with a single call, reducing code size
639 coding logic (switch statements) and because small methods further reduce
656 lead to the use of switch statements based on type or complex coding in many
1092 a system without affecting existing code and eliminates switch statements.
1095 program complexity by replacing a nested construct (switch statement) with a
1100 the nested switch statement! [Martin 92] covers some of these issues.
2398 b) Switches indicating deletion. Many applications must clear the switch to
task
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
719 including human interaction, task management, and data management details."
782 (see below) and discusses other alternatives to the task oriented models. He
1622 the ORB Task Force of the OMG.
2123 task of connecting employees with the information they need. In a
2154 The DOME system can accomplish this complex task because it offers:
2183 beyond what many of the standards require, it makes the task of
values
146 have no type, but the objects (values) they point to always do. An untyped
153 a view of types as sets of values.
223 values view taken by [Cardelli 85]. [Martin 92] provides some examples of
950 Polymorphic Languages: some values and variables may have more than one type.
1157 A type can be considered a set of values and a set of operations on those
1158 values. This can insure type-safe programming. However, the representation of
2304 particular problem with temporary values produced by C++ overloaded
works
837 based software process (TSP?). Other CMM's in the works at the SEI include a
930 "Parametric polymorphism is obtained when a function works uniformly on a range
932 polymorphism is obtained when a function works, or appears to work, on several
1732 now, and a NetWare version is in the works. Submitted a C++ language
1799 Smalltalk. This toolset works with VisualWorks from ParcPlace Systems to
2378 works well in simple cases like strings where the data is not polymorphic
2407 5. Garbage Collection Works
'
543 [Cardelli 85] and hence without polymorphism, as in '83 Ada and Modula-2.
559 Stroustrup's first edition of [Stroustrup 91, '86 p. 37] defines object based
1503 and coincidentally, MIT '82, SM '85, PhD '89 (EECS)
1730 Revision 1.0 has been shipping since beginning of '92. Revision 1.1
accessed
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
238 may be accessed wherever visible. CLOS and Ada allow methods to be defined
246 data and member functions) may be accessed from anywhere. A Stack's Push and
259 class. All Smalltalk instance variables can be accessed by subclasses,
618 encapsulation implies all arguments can be accessed by a multi-method (although
1360 objects, and hence system resources, can only be accessed if a capability to
acm
1469 Oriented Design," The Communications of ACM, (33, 9) Sept. 1990, pp. 104-1124.
2495 Software Systems", Proceedings of the 18th ACM Annual Computer
2496 Science Conference, ACM, Inc., New York, NY, 1990, pp. 161-165.
2499 Testing, Analysis, and Verification (TAV4), 1991, ACM, Inc.,
2516 ACM, Inc., pp. 68 - 80.
2561 and Applications ACM. Copies of this paper can be obtained
alternative
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
470 common subtype as its type). C++ provides an alternative, where only parents
495 otherwise. See [Raj 89] for an alternative approach as found in Jade.
665 alternative explanation. While open access can be useful in some cases, it
1322 programs, an equivalence that would be lost if an alternative were chosen, as
2409 has to show that garbage collection provides a better alternative. Early
august
11 The Smalltalk language, which was developed at Xerox PARC (by Alan Kay and others) in the 1970s, introduced the term object-oriented programming to represent the pervasive use of objects and messages as the basis for computation. Smalltalk creators were influenced by the ideas introduced in Simula 67, but Smalltalk was designed to be a fully dynamic system in which classes could be created and modified dynamically rather than statically as in Simula 67.[9] Smalltalk and with it OOP were introduced to a wider audience by the August 1981 issue of Byte Magazine.
43 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2009)
1690 Ref: Datamation, LOOK AHEAD Section, August 1. German Company.
1861 The C++ interface in August. Customers include AMD, Consilium and Swiss
1914 DOME was first released in August 1993; version 2 in May 1994.
2271 August 1993
authors
71 Responsibility-driven design defines classes in terms of a contract, that is, a class should be defined around a responsibility and the information that it shares. This is contrasted by Wirfs-Brock and Wilkerson with data-driven design, where classes are defined around the data-structures that must be held. The authors hold that responsibility-driven design is preferable.
342 In the authors opinion, a myth. The story goes an object is an instance of a
1491 The authors, regretfully, cannot supply ftp, postscript, TEX, or
2519 Conference, October 1993, Toronto. Email addresses for authors
2521 approach to testing which the authors call Testgraphs. An
2577 This paper, or one with the same title and authors, is
bank
6 An object-oriented program will usually contain different types of objects, each type corresponding to a particular kind of complex data to be managed or perhaps to a real-world object or concept such as a bank account, a hockey player, or a bulldozer. A program might well contain multiple copies of each type of object, one for each of the real-world objects the program is dealing with. For instance, there could be one bank account object for each real-world account at a particular bank. Each copy of the bank account object would be alike in the methods it offers for manipulating or reading its data, but the data inside each object would differ reflecting the different history of each account.
41 Attempts to find a consensus definition or theory behind objects have not proven very successful (however, see Abadi & Cardelli, A Theory of Objects[18] for formal definitions of many OOP concepts and constructs), and often diverge widely. For example, some definitions focus on mental activities, and some on program structuring. One of the simpler definitions is that OOP is the act of using "map" data structures or arrays that can contain functions and pointers to other maps, all with some syntactic and scoping sugar on top. Inheritance can be performed by cloning the maps (sometimes called "prototyping"). OBJECT:=>> Objects are the run time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle.
1862 Bank Corp).
black
1007 They refer to this as "best-fitting" types [Black 86]. The original Trellis
1062 similarly [Black 86].
1178 signatures can occur, calling for greater care in use. [Black 86] discusses
1196 for loosely coupled modules and in distributed programming [Black 87].
1198 Jade [Black 86] and
1260 Jade ([Black 86] and [Raj 89])
calling
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
429 inherited by any class requiring them. Method combination, or calling
432 explicitly calling them, allowing client class code to remain unchanged [Booch
1178 signatures can occur, calling for greater care in use. [Black 86] discusses
1182 calling for careful matching of actual and formal generic parameters. The
characteristics
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
105 characteristics
229 details of an object that do not contribute to its essential characteristics."
716 operational characteristics (e.g. reliability, availability, performance)".
1951 informed of the functions, attributes and characteristics of objects and
2067 characteristics -- rather than names
counting
2313 One partial solution to a lack of GC is reference counting. In this
2362 Attempts to encapsulate memory management with reference counting, the "poor
2363 man's garbage collector", are usually misguided. Reference counting has worse
2369 counting an inadequate substitute for true GC.
2377 counting to encapsulate copy-on-write memory management. However, this only
2404 d) Reference counting, which was already discussed.
coupling
513 inheritance stuctures). Some don't like the coupling of classes (as in Jade),
637 define methods for each specific case desired. In addition to better coupling
687 But coupling the two cases of selector variables (as found in CLOS,
895 lower coupling), and etc.
1097 and loose coupling. Another benefit is that code complexity increases not
1264 CLOS [Kim 89, ch 4] has a looser coupling of methods to classes and doesn't
coverage
715 statement of what is needed; a coverage of both functional and quantified
2676 TestCenter from CenterLine will do coverage testing of C++ (and C)
2681 *Graphical test coverage to highlight any code not executed during test runs
2683 *Programmatic interface to output files and cumulative code coverage
2693 voice: 1-415-957-1441, email: info@soft.com) has a coverage tool for C++
2696 San Jose, CA 95128, voice: 1-408-298-3824 ) has a coverage tool for
description
395 Defining inheritance (with a thorough description or denotational semantic
1872 Short Description:
1883 Long Description:
1925 See Appendix E:65 for a complete description and anon FTP info.
2022 Product Description -
2112 Company Description -
differing
820 A problem domain has many realizations, or differing OOAs. An OOA has many
821 realizations, or differing OODs, but a similar notation is often used for
822 the two. An OOD also has many realizations, or differing OOPs, but allows a
1052 is it? To make any difference, the differing forms must have some effect. In
1110 This also provides a good example of differing definitions among object-
2390 4. Differing Memory Management Schemes Hinder Reuse
directly
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
63 Both object-oriented programming and relational database management systems (RDBMSs) are extremely common in software today. Since relational databases don't store objects directly (though some RDBMSs have object-oriented features to approximate this), there is a general need to bridge the two worlds. The problem of bridging object-oriented programming accesses and data patterns with relational databases is known as Object-Relational impedance mismatch. There are a number of approaches to cope with this problem, but no general solution without downsides.[20] One of the most common approaches is object-relational mapping, as found in libraries like Java Data Objects and Ruby on Rails' ActiveRecord.
789 Modern OO methodologies directly address these points and emphasize the
1104 OO), called its most derived class. An object not directly contained in any
2089 object services can be implemented directly in C++)
discusses
624 [Chambers 93] discusses multi-methods in his new OO language, Cecil.
782 (see below) and discusses other alternatives to the task oriented models. He
1138 "pure" example. Section 2.5 discusses why static typing has less power
1178 signatures can occur, calling for greater care in use. [Black 86] discusses
2621 University of Durham, Durham, England. Discusses different
2633 Discusses the implications of inheritance for testing,
discussion
209 usage is atypical] See [Booch 94, pp 154-155] for a brief discussion of
462 See also [Kim 89, chs 1, 3] for a discussion and [Coplien 92] for some
463 implementation discussion in C++.
612 See also section 1.19 below for a discussion on the functional (prefix) verses
1426 See also section 1.21 for a discussion on OOA
1550 Interest Groups for discussion of possible standards in other areas. These
distribution
1520 handling distribution of messages between application objects in
1782 System Object Model with extensions for distribution. This integration will
1796 stores, and warehousing and distribution operations."
1873 DOME provides heterogenous distribution across many platforms
1889 is separated from the means of distribution and the problem of
1899 Database distribution can be as simple persistent files,
division
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
282 group division, distinction, or rating based on quality, degree of
2595 92, Computer Science Division, School of
2608 92, Computer Science Division, School of Engineering and
2620 Division, School of Engineering and Computer Science (SECS),
2630 93, Computer Science Division, School of
document
53 The Document Object Model of HTML, XHTML, and XML documents on the Internet have bindings to the popular JavaScript
186 this document also.
425 For example, a person is a mammal and an intellectual_entity, and a document
1512 (OMA) Guide document. This document outlines a single terminology for
1620 Specification described in this published document is a self-
easier
1779 have made it easier for their customers to port applications between their
1810 -- easier deployment, with the ability to run multiple HP
1816 -- easier development, with remote object browsing so
1954 requests, and has made it easier for users to integrate Orbix with their
2185 distributed environments, even easier.
2422 are generally more reliable and easier to develop, maintain, and reuse than
easily
514 but in the author's opinion many of their complaints are easily answered. In
1892 Existing software can also be incorporated easily, providing
1922 you to easily develop large distributed applications that are robust,
1945 easily integrate Orbix applications with existing data stores be they
2151 develop applications on any platform they choose and then easily
2465 confidence, they must be blatantly correct. The classes must be easily
england
1870 1st Floor, Lawrence House, 1A Morrell St, Leamington Spa, England CV32 5SZ
1964 Object World in London, England last October. Orbix for Microsoft Windows
2597 England.
2610 England. Describes a series of tools for the generation and
2621 University of Durham, Durham, England. Discusses different
2632 Durham, England.
entity
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
94 unit, or entity, either real or abstract, with a well-defined role in the
123 Entity - Correspond to real-world objects
425 For example, a person is a mammal and an intellectual_entity, and a document
1024 programming, this refers to the ability of an entity to refer at run-time to
equivalent
158 methods (Smalltalk) or member functions (C++) which are equivalent to a
162 roughly equivalent to a loosely coupled variant record, with derived classes
166 be set or respecified by a derived class. This is roughly equivalent to a
622 (messages) equivalent. Functional syntax was chosen "in order to minimize the
1072 vtables of function pointers in the actual objects (C++) or equivalent,
1261 provides one, where inheritance is replaced with a roughly equivalent form
explicit
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
919 object (possibly satisfying some implicit or explicit type constraints
956 Parametric Polymorphism: a polymorphic function has an implicit or explicit
990 Ada generics and C++ templates provide explicit syntactic generics. While
992 require explicit instantiation of its template functions, formal generic
2372 but explicit memory management requires implementation-dependent
explicitly
368 for the commonality of objects to be explicitly taken advantage of in modeling
432 explicitly calling them, allowing client class code to remain unchanged [Booch
444 class qualifier can be used to explicitly disambiguate. Smalltalk renders
496 Polymorphism is often explicitly available in many OO languages (such as C++,
2287 Without GC programmers must explicitly deallocate dynamic storage when
2375 However, to manage memory explicitly, a program has to know if it has a copy
flavors
12 In the 1970s, Kay's Smalltalk work had influenced the Lisp community to incorporate object- based techniques that were introduced to developers via the Lisp machine. Experimentation with various extensions to Lisp (like LOOPS and Flavors introducing multiple inheritance and mixins), eventually led to the Common Lisp Object System (CLOS, a part of the first standardized object-oriented programming language, ANSI Common Lisp), which integrates functional programming and object-oriented programming and allows extension via a Meta- object protocol. In the 1980s, there were a few attempts to design processor architectures that included hardware support for objects in memory but these were not successful. Examples include the Intel iAPX 432 and the Linn Smart Rekursiv.
384 Inherited parents can specify various flavors of state. Delegation languages
386 Objective-C, etc.), lisp-based (CLOS, Flavors, Scheme, etc.), and Pascal-based
427 Mixin's is a style of MI (from flavors) where a class is created to provide
443 the earlier flavors. C++ declares an error iff a conflict arises, but a
1290 Flavors
free
1376 For the Spring Papers (free), Contact:
1499 Feel free to call, fax or email for more information.
1668 > ILU (free, see APPENDIX E entry 59)
1681 Complete implementation of CORBA. Free academic; com. eval licence avail.
2288 it is no longer needed (in C this is done by a call to free(3)).
2591 Theilen, David. "No Bugs. Delivering error free code in C and C++.",
generalization
278 Original Aristotlean classification defines a "class" as a generalization of
370 classification, and generalization to understand and deal with the complexities
481 the world by using classes and concepts for generalization and categorization,
528 Generalization
531 derived classes into a common base (or parent) is generalization [Booch 91,
1388 a generalization of the Rider
generic
952 have more than one type. [...] If we consider a generic function to be
991 Ada may infer some actual generic parameters (operations) and C++ doesn't
992 require explicit instantiation of its template functions, formal generic
1182 calling for careful matching of actual and formal generic parameters. The
1232 Functions are typically generic in statically-typed parametrically-polymorphic
1234 are generic. Russell and Haskel are more modern variants (references are
guide
1512 (OMA) Guide document. This document outlines a single terminology for
1602 > Object Management Architecture Guide (OMA)
1631 Architecture (OMA) Guide for $50 each.
1937 approach to filtering, and more code examples to guide programmers.
2626 papers. Get "guide.ps.Z" for A4 paper formatting or get
2639 Wong, P. Automated Class Exerciser (ACE) User's Guide. Technical
hp's
770 best features from several of the major OO methodologies, as does HP's new
1747 HP ORB Plus and HP Distributed Smalltalk are major components of HP's
1775 tools, and sample applications. HP's DOMF provides a location-transparent
1781 In addition, HP is working with IBM to integrate HP's DOMF with IBM's
1819 HP's DOMF includes the object request broker, interface- definition-
1827 HP's limited release of HP ORB Plus to key developers is designed so that
humphrey
779 See [Humphrey 89] and [Yourdon 92] for a few of many discussions on software
780 life-cycle models and their use. Humphrey also details Worldy and Atomic
832 in the US [Humphrey 89]. The CMM also serves as a 5 level improvement process
835 Humphrey is now working on the Personal Software Process (PSP), a scaled down
836 version of the CMM for individuals [Humphrey 95]. Next should follow a team-
856 Humphrey, W., Snyder, T. and Willis, R. "Software Process Improvement at
ieee
857 Hughes Aircraft", IEEE Software, July 1991
858 Dion, R., "Elements of a Process Improvement Program," IEEE Software, July
1456 International Conference on System Sciences (HICSS) (IEEE Computer Society
2524 Maintenance, pp. 100-105. IEEE Computer Society, October 1989.
2544 Object-Oriented Programs", IEEE Software, July 1991, pp. 72-80.
2585 Conference on Software Maintenance 1990, IEEE Computer Society
improvement
73 Luca Cardelli wrote a paper titled "Bad Engineering Properties of Object-Oriented Languages" Richard Stallman wrote in 1995, "Adding OOP to Emacs is not clearly an improvement; I used OOP when working on the Lisp Machine window systems, and I disagree with the usual view that it is a superior way to program."
832 in the US [Humphrey 89]. The CMM also serves as a 5 level improvement process
834 leading to statistical (process) control and sustained improvement. Watts S.
856 Humphrey, W., Snyder, T. and Willis, R. "Software Process Improvement at
858 Dion, R., "Elements of a Process Improvement Program," IEEE Software, July
860 "Concepts on Measuring the Benefits of Software Process Improvement,"
included
12 In the 1970s, Kay's Smalltalk work had influenced the Lisp community to incorporate object- based techniques that were introduced to developers via the Lisp machine. Experimentation with various extensions to Lisp (like LOOPS and Flavors introducing multiple inheritance and mixins), eventually led to the Common Lisp Object System (CLOS, a part of the first standardized object-oriented programming language, ANSI Common Lisp), which integrates functional programming and object-oriented programming and allows extension via a Meta- object protocol. In the 1980s, there were a few attempts to design processor architectures that included hardware support for objects in memory but these were not successful. Examples include the Intel iAPX 432 and the Linn Smart Rekursiv.
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
1314 Refs to be included in future FAQs.
1355 Refs to be included in future FAQs. See also Appendix E.
inherent
482 by reducing the real-world's inherent complexity.
644 ignoring the inherent type of parameters in messaging. Double dispatch is
652 inherent (true, actual, or dynamic) types of one and two. Only the inherent
1005 but lose the inherent type). Any object possessing all required operations is
1116 inherent types of polymorphic objects, keeping track of the types of objects at
instantiation
406 instantiation relationship. In classical OO, inheritance is a relationship
407 between classes only. In one-level systems, is-a (object instantiation) and
590 systems, since any object may act as a class (provide object instantiation or
966 where each instantiation creates a specialized version of the code allowing
992 require explicit instantiation of its template functions, formal generic
1255 object instantiation, or exemplars.
int
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
627 +(int, int)
628 +(int, float)
629 +(int, complex)
630 +(int, real)
issue
11 The Smalltalk language, which was developed at Xerox PARC (by Alan Kay and others) in the 1970s, introduced the term object-oriented programming to represent the pervasive use of objects and messages as the basis for computation. Smalltalk creators were influenced by the ideas introduced in Simula 67, but Smalltalk was designed to be a fully dynamic system in which classes could be created and modified dynamically rather than statically as in Simula 67.[9] Smalltalk and with it OOP were introduced to a wider audience by the August 1981 issue of Byte Magazine.
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
261 Another issue is per-object or per-class protection. Per-class protection
440 which to choose becomes an issue. Eiffel forces derived classes to rename
1179 this issue in Emerald. The same issue arises in parametric polymorphism
jade
46 Languages called "pure" OO languages, because everything in them is treated consistently as an object, from primitives such as characters and punctuation, all the way up to whole classes, prototypes, blocks, modules, etc. They were designed specifically to facilitate, even enforce, OO methods. Examples: Scala, Smalltalk, Eiffel, JADE, Emerald.
495 otherwise. See [Raj 89] for an alternative approach as found in Jade.
513 inheritance stuctures). Some don't like the coupling of classes (as in Jade),
1198 Jade [Black 86] and
1260 Jade ([Black 86] and [Raj 89])
1278 Jade
john
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
26 Similarly, in his 2003 book, Concepts in programming languages, John C. Mitchell identifies four main features: dynamic dispatch, abstraction, subtype polymorphism, and inheritance.Michael Lee Scott in Programming Language Pragmatics considers only encapsulation, inheritance and dynamic dispatch.[16]
57 Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1995 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, sometimes casually called the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. As of April 2007, the book was in its 36th printing.
2513 Harrold, Mary Jean, John D. McGregor, and Kevin J. Fitzpatrick,
2530 Lakos, John S. "Designing-In Quality in Large C++ Projects" Presented
2542 to "john_lakos@warren.mentorg.com".
june
1433 June 1991
1860 the Smalltalk and Objective-C language interfaces is expected in June.
1938 Orbix was launched in June 1993 as the first full and complete implementation
1960 exhibition in San Francisco, Calif., June 1993. Since then it has rolled
2572 Programming, June, 1991, Vol. 4, No. 3, pp. 10 - 27.
2574 Programs", JOOP, 5(3):45-53, June 1992.
key
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
110 covers "Identifying Key Abstractions" for objects and classes based on an
733 The key to reusable software is captured in domain analysis in that it
1519 1) the Object Request Broker, or key communications element, for
1827 HP's limited release of HP ORB Plus to key developers is designed so that
2537 design becomes a key factor only for large and very
mapping
62 Main articles: Object-Relational impedance mismatch, Object-relational mapping, and Object database
63 Both object-oriented programming and relational database management systems (RDBMSs) are extremely common in software today. Since relational databases don't store objects directly (though some RDBMSs have object-oriented features to approximate this), there is a general need to bridge the two worlds. The problem of bridging object-oriented programming accesses and data patterns with relational databases is known as Object-Relational impedance mismatch. There are a number of approaches to cope with this problem, but no general solution without downsides.[20] One of the most common approaches is object-relational mapping, as found in libraries like Java Data Objects and Ruby on Rails' ActiveRecord.
65 OOP can be used to associate real-world objects and processes with digital counterparts. However, not everyone agrees that OOP facilitates direct real-world mapping (see Negative Criticism section) or that real-world mapping is even a worthy goal; Bertrand Meyer argues in Object-Oriented Software Construction that a program is not a model of the world but a model of some part of the world; "Reality is a cousin twice removed". At the same time, some principal limitations of OOP had been noted. For example, the Circle-ellipse problem is difficult to handle using OOP's concept of inheritance.
1733 mapping for IDL to the OMG recently.
2088 Languages used for IDL mapping - IDL bindings for C, (or
meaning
101 object as a concept, abstraction or thing with crisp boundaries and meaning for
237 Object Pascal provide no protection for objects, meaning instance variables
268 A class is a general term denoting classification and also has a new meaning
815 the process is often referred to as seamless, meaning there is no conceptual
1076 The run-time selection of methods is another case of dynamic binding, meaning
1888 DOME is non-intrusive, meaning that the application development
mi
427 Mixin's is a style of MI (from flavors) where a class is created to provide
448 several classes. In classical systems without MI, a class which should inherit
520 strategies or renaming, and most consider MI to be highly desirable. See the
521 latter part of section 1.9 for an example of why MI is important.
522 Some prefer association to MI, claiming "roles" (as defined in [Rumbaugh 91])
987 MI provides an interesting example here, as it is set intersection with an
modula-
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
50 Languages with abstract data type support, but not all features of object-orientation, sometimes called object-based languages. Examples: Modula-2 (with excellent encapsulation and information hiding), Pliant, CLU.
387 (Ada95, Modula-3, Object Pascal, etc.) OO languages do, but with multiple-
543 [Cardelli 85] and hence without polymorphism, as in '83 Ada and Modula-2.
545 provide inheritance and polymorphism. Ada95 and Modula-3; however, support
1304 Modula-3
modular
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
21 Dynamic dispatch – when a method is invoked on an object, the object itself determines what code gets executed by looking up the method at run time in a table associated with the object. This feature distinguishes an object from an abstract data type (or module), which has a fixed (static) implementation of the operations for all instances. It is a programming methodology that gives modular component development while at the same time being very efficient.
1605 a methodology that supports modular production of software;
2543 Leavens, G. T., "Modular Specification and Verification of
networks
1776 object-communication mechanism across heterogeneous networks by using the
1874 and networks, including:
2024 for building computing applications and services on networks
2031 networks
2045 computers, operating systems and networks
2048 networks of heterogeneous computers, operating
nt
1642 IBM AIX, IBM MVS(port in progress), HP-UX, Macintosh, MS-Windows 3.1, NT,
1807 3.1 or Windows NT operating systems from Microsoft(R) Corp., once
1875 UNIX, Windows, Windows NT, OS
1961 out versions of Orbix for Microsoft Windows NT, Silicon Graphics IRIX and
1993 Microsoft Windows NT Visual C++ NOW
1994 Microsoft Windows NT Borland NOW
object-based
50 Languages with abstract data type support, but not all features of object-orientation, sometimes called object-based languages. Examples: Modula-2 (with excellent encapsulation and information hiding), Pliant, CLU.
541 1.15) What Is The Difference Between Object-Based And Object-Oriented? (Object-Oriented Technology)
542 Object-Based Programming usually refers to objects without inheritance
1744 With HP ORB Plus, programmers can develop scalable, object-based
1792 executive officer of Information Advantage, Inc. "Our object-based
1794 We plan to use HP ORB Plus to develop new object-based products that
opposed
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
33 Decoupling refers to careful controls that separate code modules from particular use cases, which increases code re-usability. A common use of decoupling in OOP is to polymorphically decouple the encapsulation (see Bridge pattern and Adapter pattern) - for example, using a method interface which an encapsulated object must satisfy, as opposed to using the object's class.
276 objects (as opposed to a collection of objects, as with the more classical
377 programming by extension (as opposed to programming by reinvention
1153 Subtype Polymorphism, as opposed to Subclass Polymorphism, is the best answer
1318 opposed to a purely value-oriented approach) and because of support for methods
orbeline
1680 > ORBELINE - The SMART Object Request Broker - PostModern Computing
1683 1 versions of ORBeline available; will
1918 CORBA Implementation Descriptions: ORBELINE - The SMART Object Request Broker
1919 ORBeline is a complete implementation of OMG's Common Object Request
1920 Broker Architecture (CORBA). ORBeline goes beyond the standard
1923 scalable, flexible and maintainable. ORBeline incorporates PostModern's
parameter
160 first parameter. The receiver is called self (Smalltalk) or this (C++).
598 operation. It can be thought of as a procedure with the first parameter as
607 although keywords (or formal parameter names, like named parameters) are
617 more than one parameter can be used in the selection of a method. Lack of
957 type parameter which determines the type of the argument for each
1049 object (pointer or reference (or such parameter)) is assignment compatible with
perspective
80 Steve Yegge, making a roundabout comparison with Functional programming, writes, "Object Oriented Programming puts the Nouns first and foremost. Why would you go to such lengths to put one part of speech on a pedestal? Why should one kind of concept take precedence over another? It's not as if OOP has suddenly made verbs less important in the way we actually think. It's a strangely skewed perspective."
747 expert's perspective and with an emphasis on modeling the real-world (the
794 an overall system perspective and [Berard 93] proposes an (incremental)
829 From a greater perspective, the SEI has developed the Capability Maturity Model
873 efforts places information systems within an organizational perspective by
2232 perspective, the enterprise is a single logical database located in
physical
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
1526 the logical modeling and physical storage of objects; and
2230 to know the physical location of data, the server of access, or the
2235 enterprise's physical environment of multiple nodes, disparate
2536 hierarchical testing. The importance of good physical
platform
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
1851 Isis RDOM(tm) is a fault tolerant distributed ORB platform for reliable
2151 develop applications on any platform they choose and then easily
2166 and its open platform structure accommodates future technologies.
2210 - Platform independent time services and exception handling
2263 platform. SUITESOFTWARE sales representatives are available to help
pointer
144 Descriptor-based approaches can have pointer semantics and can be statically
147 pointer (such as void* in C++) and an embedded dynamic typing scheme are used
167 pointer or function pointer in the base class being set by the derived class.
601 which do not have a receiver, or "this" pointer. The following are some common
1049 object (pointer or reference (or such parameter)) is assignment compatible with
proceedings
2330 in Memory Management (proceedings of 1992 Int'l Workshop on Memory
2495 Software Systems", Proceedings of the 18th ACM Annual Computer
2498 Object-Oriented Programs", Proceedings of the 4th Symposium on
2503 Firesmith, D.G., "Testing Object-Oriented Software", Proceedings
2506 Object-Oriented Programs", Proceedings of the 8th Pacific
2584 Problems of Validation", Proceedings of the 6th International
project
7 Objects can be thought of as wrapping their data within a set of functions designed to ensure that the data are used appropriately, and to assist in that use. The object's methods will typically include checks and safeguards that are specific to the types of data the object contains. An object can also offer simple-to-use, standardized methods for performing particular operations on its data, while concealing the specifics of how those tasks are accomplished. In this way alterations can be made to the internal structure or methods of an object without requiring that the rest of the program be modified. This approach can also be used to offer standardized methods across different types of objects. As an example, several different types of objects might offer print methods. Each type of object might implement that print method in a different way, reflecting the different kinds of data each contains, but all the different print methods might be called in the same standardized manner from elsewhere in the program. These features become especially useful when more than one programmer is contributing code to a project or when the goal is to reuse code between projects.
839 Level 1: Initial: Every project is handled differently; ad hoc and chaotic.
840 Level 2: Repeatable: Every project is handled similarly.
1371 Ouverture Project (ESPRIT funded OMG IDL defines inter-module interfaces)
1712 Electra is a research project and not available yet.
2483 Berard, Edward. Project Management Handbook. Must be purchased
projects
7 Objects can be thought of as wrapping their data within a set of functions designed to ensure that the data are used appropriately, and to assist in that use. The object's methods will typically include checks and safeguards that are specific to the types of data the object contains. An object can also offer simple-to-use, standardized methods for performing particular operations on its data, while concealing the specifics of how those tasks are accomplished. In this way alterations can be made to the internal structure or methods of an object without requiring that the rest of the program be modified. This approach can also be used to offer standardized methods across different types of objects. As an example, several different types of objects might offer print methods. Each type of object might implement that print method in a different way, reflecting the different kinds of data each contains, but all the different print methods might be called in the same standardized manner from elsewhere in the program. These features become especially useful when more than one programmer is contributing code to a project or when the goal is to reuse code between projects.
841 Level 3: Defined: Standard processes are defined and used for all projects.
2486 The book focuses on the management of OOP projects. It
2530 Lakos, John S. "Designing-In Quality in Large C++ Projects" Presented
2538 large projects. Intuition gained from smaller projects
protection
227 1.2) What Is Object Encapsulation (Or Protection)? (Object-Oriented Technology)
237 Object Pascal provide no protection for objects, meaning instance variables
244 protection
261 Another issue is per-object or per-class protection. Per-class protection
264 receiver in per-object protection. This supports a subtyping model, as any
protocols
356 perform differential changes, intercessory protocols allow users to not
1764 operating systems, networking protocols or where application objects are
2036 OSI protocols, X.25
2127 systems, applications, databases, network protocols, and the like.
2137 differences between operating systems, network protocols, databases,
2205 - Implementation of additional protocols through a
prototype
59 Creational patterns : Factory method pattern, Abstract factory pattern, Singleton pattern, Builder pattern, Prototype pattern
205 term "Prototype" usually refers to prototype theory, a recent theory of
207 prototype for newly created instances. [The Author also uses the term for
210 prototype theory in the context of OOA and OOD.
291 (conceptual descriptions), and prototype theory (resemblance to an exemplar).
remote
1693 support for heterogeneous environments, support for Remote Data Access
1694 (RDA), Remote Procedure Calls (RPC), Message-Oriented Middleware (MOM),
1813 sending and receiving of remote messages, and reusable
1816 -- easier development, with remote object browsing so
2159 - and support for Remote Data Access (RDA), Remote Procedure
requests
130 Wildavsky, send requests to adamw@panix.com.
1530 The OMG adoption cycle includes Requests for Information and
1616 requests and receive responses. The ORB provides interoperability
1771 make requests and receive responses across a distributed network.
1954 requests, and has made it easier for users to integrate Orbix with their
2231 underlying vendor in order to process requests. From the user's
result
19 Not all of these concepts are to be found in all object-oriented programming languages. For example, object-oriented programming that uses classes is sometimes called class-based programming, while prototype-based programming does not typically use classes. As a result, a significantly different yet analogous terminology is used to define the concepts of object and instance.
199 concept, will result. Typical 1 Level objects can contain any number of
501 class. Such assignment can result in the loss of an object's dynamic type in
2141 As a result, middleware is quickly emerging as the best solution for
2294 interpreters often suffer from this. The usual result is that the
2316 is inefficient (swapping two references will result in three
reusable
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
57 Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1995 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, sometimes casually called the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. As of April 2007, the book was in its 36th printing.
733 The key to reusable software is captured in domain analysis in that it
739 Object-oriented domain analysis (OODA) seeks to identify reusable items
1813 sending and receiving of remote messages, and reusable
richard
57 Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1995 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, sometimes casually called the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. As of April 2007, the book was in its 36th printing.
73 Luca Cardelli wrote a paper titled "Bad Engineering Properties of Object-Oriented Languages" Richard Stallman wrote in 1995, "Adding OOP to Emacs is not clearly an improvement; I used OOP when working on the Lisp Machine window systems, and I disagree with the usual view that it is a superior way to program."
79 Richard Mansfield, author and former editor of COMPUTE! magazine, states that "like countless other intellectual fads over the years ("relevance", communism, "modernism", and so on—history is littered with them), OOP will be with us until eventually reality asserts itself. But considering how OOP currently pervades both universities and workplaces, OOP may well prove to be a durable delusion. Entire generations of indoctrinated programmers continue to march out of the academy, committed to OOP and nothing but OOP for the rest of their lives."[38] He also is quoted as saying "OOP is to writing a program, what going through airport security is to flying".
1497 Contact Person: Richard Soley (technical director) soley@omg.com
1500 -- Richard Soley
1791 our entire company on it," said Richard Tanler, president and chief
robson
2573 Smith, M. D. and D. J. Robson, " A Framework for Testing Object-Oriented
2583 Smith, M. D. and D. J. Robson, "Object-Oriented Programming - the
2593 Turner, C. D. and D. J. Robson, "The Testing of Object-Oriented Programs",
2605 Turner, C. D. and D. J. Robson, "A Suite of Tools for the State-Based
2617 Turner, C. D. and D. J. Robson, "Guidance for the Testing of Object-
2628 Turner, C. D. and D. J. Robson, "State-Based Testing and Inheritance",
selection
617 more than one parameter can be used in the selection of a method. Lack of
682 There is some concern about the efficiency of run-time method selection as
685 literature, potentially providing a single static selection in many cases
690 and run-time selection (or checking) as unavoidable in the general case [a
823 selection from among various languages for implementation (choosing the best
1076 The run-time selection of methods is another case of dynamic binding, meaning
semantics
144 Descriptor-based approaches can have pointer semantics and can be statically
287 The intension of a class is its semantics and its extension is its instances
403 existing uses and semantics.
2364 performance than GC, awkward syntax, and poor semantics, which typically
2374 often use "copy on write" to efficiently implement pass-by-value semantics.
2401 c) Value semantics store objects rather than references, inhibiting data
separate
22 Encapsulation (or multi-methods, in which case the state is kept separate)
33 Decoupling refers to careful controls that separate code modules from particular use cases, which increases code re-usability. A common use of decoupling in OOP is to polymorphically decouple the encapsulation (see Bridge pattern and Adapter pattern) - for example, using a method interface which an encapsulated object must satisfy, as opposed to using the object's class.
190 languages. Since there is no separate class construct in these languages, and
568 object facility. Separate type system support is another extension.
963 related, but are distinct enough in implementation to justify separate
1008 Owl also had such a facility but with two separate inheritance hierarchies,
size
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
171 switch statement on variant parts with a single call, reducing code size
1229 dependencies and expand code size (unlike a single-body or "true"
1576 size <segment size> (max file size to send)
smalltalk's
138 approach with an added layer of indirection to Smalltalk's handles is found
255 For another example, Smalltalk's class instance variables are not accessible
257 Smalltalk's methods are all public (can be invoked from anywhere), but a
333 class class (Smalltalk's Meta-Classes)
566 even migrate across machines. Distributed Smalltalk's proxy objects [Kim 89,
1149 However, Smalltalk's style uses inclusion polymorphism in practise and
statically-typed
154 Simple statically-typed objects (static and auto vars and temps in C++ and
1064 Dynamic binding has two forms, static and dynamic. Statically-typed dynamic
1073 providing statically-typed dynamic binding (this is really just defining simple
1119 statically-typed OO languages provide polymorphism. Some approaches provide
1232 Functions are typically generic in statically-typed parametrically-polymorphic
1272 Statically-Typed:
strachey's
925 many different forms. Computer Science refers to Strachey's original
929 > Strachey's Original Definition [Strachey 67]:
938 C+W refine Strachey's definition by adding "inclusion polymorphism" to model
939 subtypes and subclasses (inheritance). Strachey's parametric polymorphism is
1144 "pure" statically (or strongly) checked parametric polymorphism, by Strachey's
1148 parametric polymorphism without static constraints (by Strachey's definition).
terminology
19 Not all of these concepts are to be found in all object-oriented programming languages. For example, object-oriented programming that uses classes is sometimes called class-based programming, while prototype-based programming does not typically use classes. As a result, a significantly different yet analogous terminology is used to define the concepts of object and instance.
183 derived class terminology
185 super-class terminology, and is preferred in
351 terminology, an introspective protocol provides a read only capability (e.g.
1102 Yes (but be careful of context). To use C++ terminology, an object (not
1512 (OMA) Guide document. This document outlines a single terminology for
things
67 Steve Yegge and others noted that natural languages lack the OOP approach of strictly prioritizing things (objects
103 of a set of real-world things such that:
104 * all of the real-world things in the set - the instances - have the same
107 and on identifying objects: "What are the *things* in this problem? Most of
108 the things are likely to fall into the following five categories: Tangible
109 things, Roles, Incidents, Interactions, and Specifications." [Booch 91, 4.3]
tm
1759 the Open Software Foundation(tm) as its transport mechanism. DCE is
1849 Product: Isis Reliable Distributed Object Manager(tm) (RDOM)
1851 Isis RDOM(tm) is a fault tolerant distributed ORB platform for reliable
1855 Toolkit(tm). RDOM provides interfaces from Smalltalk (Parcplace),
2016 NCR Cooperative Frameworks(TM) were first released for sale
2018 1991 as "the frameworks" part of the NCR COOPERATION(TM)
tool
2425 and garbage collection is much too important a tool to be absent from any
2655 IPL Ltd. (in the UK) has a testing tool called Cantata which allows for
2659 making the tool exceptionally easy to use and productive in
2688 MicroTech Pacific Research (mpr.ca) has a C++ class testing tool called
2693 voice: 1-415-957-1441, email: info@soft.com) has a coverage tool for C++
2696 San Jose, CA 95128, voice: 1-408-298-3824 ) has a coverage tool for
users
350 Meta-Classes accessible to users [Kiczales 92, Paepcke 93]. In CLOS
356 perform differential changes, intercessory protocols allow users to not
1783 eventually provide users with complete scalability, portability and
1787 system administrators and end users language-neutral, enterprise-wide,
1795 retailers can distribute to end users throughout headquarters, all chain
1954 requests, and has made it easier for users to integrate Orbix with their
usual
73 Luca Cardelli wrote a paper titled "Bad Engineering Properties of Object-Oriented Languages" Richard Stallman wrote in 1995, "Adding OOP to Emacs is not clearly an improvement; I used OOP when working on the Lisp Machine window systems, and I disagree with the usual view that it is a superior way to program."
695 OOP stands for Object-Oriented Programming, the usual programming
777 The usual progression is from OOA to OOD to OOP (implementation) and this
1237 This refers to the usual class and object model. Its any 2+ level system
2294 interpreters often suffer from this. The usual result is that the
2575 Describes ways in which the usual approach to software testing
visual
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
48 Languages that are historically procedural languages, but have been extended with some OO features. Examples: Visual Basic (derived from BASIC), Fortran 2003, Perl, COBOL 2002, PHP, ABAP.
1993 Microsoft Windows NT Visual C++ NOW
1995 Microsoft Windows 3.1 Visual C++ In Beta
2241 Powerbuilder,, Visual Basic,, and Uniface,. Among the CASE tools are
accessing
5 In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are either bundled in with the data or inherited from "class objects." These act as the intermediaries for retrieving or modifying the data they control. The programming construct that combines data with a set of methods for accessing and managing those data is called an object. The practice of using subroutines to examine or modify certain kinds of data, however, was also quite commonly used in non-OOP modular programming, well before the widespread use of object-oriented programming.
436 inheritance by simply accessing the first name encountered for data members
437 and by accessing the first signature match (or ambiguity) encountered for
1071 usage must have a consistent way of accessing these functions, as achieved thru
2146 application in the enterprise, accessing virtually any data.
actors
116 Use-Cases and Actors - Actors <--> Use-Cases <--> Object Model Objects
458 or change parents from objects (or classes) at run-time. Actors, CLOS, and
1032 as found in several dynamically typed OO languages such as Actors, CLOS,
1288 Actors Languages
adopted
774 should be made into a public standard, perhaps to be adopted by the OMG. The
1536 Adopted specifications are available on a fee-free basis to members and
1538 In late 1991 OMG adopted its first interface technology, for the Object
1539 Request Broker portion of the reference model. This technology, adopted
2187 its products to industry standards as they are adopted.
assume
56 It is intuitive to assume that inheritance creates a semantic "is a" relationship, and thus to infer that objects instantiated from subclasses can always be safely used instead of those instantiated from the superclass. This intuition is unfortunately false in most OOP languages, in particular in all those that allow mutable objects. Subtype polymorphism as enforced by the type checker in OOP languages (with mutable objects) cannot guarantee behavioral subtyping in any context. Behavioral subtyping is undecidable in general, so it cannot be implemented by a program (compiler). Class or object hierarchies need to be carefully designed considering possible incorrect uses that cannot be detected syntactically. This issue is known as the Liskov substitution principle.
912 Polymorphism is the ability of an object (or reference) to assume (be replaced
918 polymorphism, which allows an object (or reference) to assume or become any
924 many uses in the sciences, all referring to objects that can take on or assume
2611 execution of test cases for OOP. These tools assume a
calls
113 driven design. Jacobson also calls for managing complexity with specialized
876 [Yourdon 92] even calls for "global modeling"!
1694 (RDA), Remote Procedure Calls (RPC), Message-Oriented Middleware (MOM),
2160 Calls (RPC), Message-Oriented Middleware (MOM), and Object Request
2421 scheduling destructor calls smoothly. Of course, garbage collected programs
cantata
2655 IPL Ltd. (in the UK) has a testing tool called Cantata which allows for
2658 Cantata allows testing to be performed in an intuitive way
2660 operation. Cantata is suitable for testing software written in
2662 Cantata provides comprehensive facilities for all forms of
2664 testing, unit testing and integration testing. Cantata has been
chambers
218 Chambers has proposed an interesting variation called "Predicate Classes"
219 [Chambers 93] as a part of his Cecil language. These classes will only be
624 [Chambers 93] discusses multi-methods in his new OO language, Cecil.
686 [See Agrawal 91, Chambers 92, Mugridge 91, and etc.].
1090 (such as found in [Agrawal 91] and [Chambers 92]).
citation
8 Object-oriented programming has roots that can be traced to the 1960s. As hardware and software became increasingly complex, manageability often became a concern. Researchers studied ways to maintain software quality and developed object-oriented programming in part to address common problems by strongly emphasizing discrete, reusable units of programming logic[citation needed]. The technology focuses on data rather than processes, with programs composed of self-sufficient modules ("classes"), each instance of which ("objects") contains all the information needed to manipulate its own data structure ("members"). This is in contrast to the existing modular programming that had been dominant for many years that focused on the function of a module, rather than specifically the data, but equally provided for code reuse, and self-sufficient reusable units of programming logic, enabling collaboration through the use of linked modules (subroutines). This more conventional approach, which still persists, tends to consider data and behavior separately.
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
17 Just as procedural programming led to refinements of techniques such as structured programming, modern object-oriented software design methods include refinements[citation needed] such as the use of design patterns, design by contract, and modeling languages (such as UML).
closely
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
66 However, Niklaus Wirth (who popularized the adage now known as Wirth's law: "Software is getting slower more rapidly than hardware becomes faster") said of OOP in his paper, "Good Ideas through the Looking Glass", "This paradigm closely reflects the structure of systems 'in the real world', and it is therefore well suited to model complex systems with complex behaviours" (contrast KISS principle).
940 divided into parametric and inclusion polymorphism, which are closely related,
962 The two forms of "Universal Polymorphism", parametric and inclusion are closely
2298 modules must co-operate closely. This leads to a tight binding
combination
54 ECMAScript language. JavaScript is perhaps the best known prototype- based programming language, which employs cloning from prototypes rather than inheriting from a class. Another scripting language that takes this approach is Lua. Earlier versions of ActionScript (a partial superset of the ECMA-262 R3, otherwise known as ECMAScript) also used a prototype-based object model. Later versions of ActionScript incorporate a combination of classification and prototype-based object models based largely on the currently incomplete ECMA-262 R4 specification, which has its roots in an early JavaScript 2 Proposal. Microsoft's JScript.NET also includes a mash-up of object models based on the same proposal, and is also a superset of the ECMA-262 R3 specification.
429 inherited by any class requiring them. Method combination, or calling
538 is a combination of overloading and multiple-polymorphism because parameters do
1882 using any combination of the above.
1900 RDBMSs, OODMS, or a combination of these.
component
21 Dynamic dispatch – when a method is invoked on an object, the object itself determines what code gets executed by looking up the method at run time in a table associated with the object. This feature distinguishes an object from an abstract data type (or module), which has a fixed (static) implementation of the operations for all instances. It is a programming methodology that gives modular component development while at the same time being very efficient.
124 Component Objects - Utility and Implementation hiding objects
231 used when developing an overall program structure, that each component of a
2358 of the component nearly impossible. For example, methods and functions
2534 designing software that avoids acyclic component
consistent
475 default. This allows a finer granularity of control and consistent name
714 of externally observable behavior; a complete, consistent, and feasible
890 equivalence" with the RW than other methodologies), a consistent and seamless
1071 usage must have a consistent way of accessing these functions, as achieved thru
1941 distributed, object oriented applications following a consistent and
constructed
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
1252 This makes for easy "prototyping", which allows for objects to be constructed
1894 DOME is constructed as a C++ class library, from which ORBs
1895 can be configured and constructed to best suit the runtime
2469 constructed in a way which is recognized as correct and the modules
copies
6 An object-oriented program will usually contain different types of objects, each type corresponding to a particular kind of complex data to be managed or perhaps to a real-world object or concept such as a bank account, a hockey player, or a bulldozer. A program might well contain multiple copies of each type of object, one for each of the real-world objects the program is dealing with. For instance, there could be one bank account object for each real-world account at a particular bank. Each copy of the bank account object would be alike in the methods it offers for manipulating or reading its data, but the data inside each object would differ reflecting the different history of each account.
1459 may continue to request hard copies. We are currently extending the paper
2541 Copies of the postscript file can be obtained by sending email
2556 Foundations, Champaign, Illinois, 1992. Copies may be obtainable
2561 and Applications ACM. Copies of this paper can be obtained
copy
6 An object-oriented program will usually contain different types of objects, each type corresponding to a particular kind of complex data to be managed or perhaps to a real-world object or concept such as a bank account, a hockey player, or a bulldozer. A program might well contain multiple copies of each type of object, one for each of the real-world objects the program is dealing with. For instance, there could be one bank account object for each real-world account at a particular bank. Each copy of the bank account object would be alike in the methods it offers for manipulating or reading its data, but the data inside each object would differ reflecting the different history of each account.
1630 o I would like to order ______ copy(s) of the Object Management
1632 o I would like to order ______ copy(s) of the CORBA for $50 each.
2374 often use "copy on write" to efficiently implement pass-by-value semantics.
2375 However, to manage memory explicitly, a program has to know if it has a copy
corp
1540 from a joint proposal (named "CORBA") of Hewlett-Packard, NCR Corp.,
1541 HyperDesk Corp., Digital Equipment Corp., Sun Microsystems and Object
1807 3.1 or Windows NT operating systems from Microsoft(R) Corp., once
1862 Bank Corp).
create
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
530 To create a subclass is specialization, to factor out common parts of
1228 efficiency tradeoff), and sources can cause inlining and create source code
1327 OODBs) that outlive the programs that create them. Object lifetimes can be
1823 interfaces to use objects effectively. So developers don't need to create
creating
16 More recently, a number of languages have emerged that are primarily object-oriented yet compatible with procedural methodology, such as Python and Ruby. Probably the most commercially important recent object-oriented languages are Visual Basic.NET (VB.NET) and C#, both designed for Microsoft's .NET platform, and Java, developed by Sun Microsystems. Both frameworks show the benefit of using OOP by creating an abstraction from implementation in their own way. VB.NET and C# support cross-language inheritance, allowing classes defined in one language to subclass classes defined in the other language. Developers usually compile Java to bytecode, allowing Java to run on any operating system for which a Java virtual machine is available. VB.NET and C# make use of the Strategy pattern to accomplish cross-language inheritance, whereas Java makes use of the Adapter pattern[citation needed].
421 by making a small change to a class. Creating a subclass to alter a method
1800 provide programmers with a rapid development environment for creating and
2029 architecture and methodology for creating
2184 creating distributed applications, especially in very large
ddm
2226 DDM provides autonomy for distributed data sites, but it also
2233 its entirety on the local machine. This is possible because DDM maps
2237 DDM can manipulate data across a large number of databases and data
2239 Access Group's Call Level Interface standard, DDM can interoperate
2244 DOME, DOMEshell, DOME Security, DOME Data Manager, and DDM are
default
383 respecify state by default.
385 don't specify new state by default (to do so requires cloning), C-based (C++,
389 provide this as a default at the level of slots and features, respectively).
475 default. This allows a finer granularity of control and consistent name
1329 automatics having the shortest default
delegate
197 sharing and often instances will simply delegate to parents to access methods
215 search for an attribute to a delegate, and is therefore more of a pure
1245 to one of its base classes. In delegation systems, each object has a delegate
1247 on message passing where an object could delegate responsibility of a message
1249 object can be added to the delegate list, giving dynamic inheritance (of a
designs
4 Objects are used in software development to implement abstract data structures, by bringing together the data components with the procedures that manipulate them. Objects in object- oriented programming are key in the concept of inheritance; thereby improving program reliability[attribution needed], simplification of software maintenance[attribution needed], the management of libraries, and the division of work in programmer teams. Object-oriented programming languages are generally designed to exploit and enforce these potential advantages of the object model. Objects can also make it possible to handle very disparate objects by the same piece of code, as long as they all have the proper method. Simple, non-OOP programs may be one "long" list of statements (or commands). More complex programs will often group smaller sections of these statements into functions or subroutines each of which might perform a particular task. With designs of this sort, it is common for some of the program's data to be 'global', i.e. accessible from any part of the program. As programs grow in size, allowing any function to modify any piece of data means that bugs can have wide-reaching effects.
1392 It reviews other designs such as Clouds and Choices which where written
1393 It reviews other designs such as Clouds and Choices which where written
1394 on C++. [[ The lack of type-tests in C++ was a problem in other designs.]]
2539 leads to errors in large designs. Compile-coupling
desired
637 define methods for each specific case desired. In addition to better coupling
1077 lookup is performed (bound) at run-time (dynamically). This is often desired
1187 It is possible to specify desired abstract properties of type specifications
1244 derived class does not have a desired attribute, it "delegates" responsibility
2411 mark-and-sweep that left much to be desired. However, garbage collection has
determine
2264 determine configuration requirements for particular computer systems.
2357 determine the last use of an object and provide deletion. This makes reuse
2360 about the rest of the program to determine ownership of the objects in the
2385 different threads) makes it impossible to statically determine the last user
2656 testing C++, but as far as I am able to determine, it has no special
digital
65 OOP can be used to associate real-world objects and processes with digital counterparts. However, not everyone agrees that OOP facilitates direct real-world mapping (see Negative Criticism section) or that real-world mapping is even a worthy goal; Bertrand Meyer argues in Object-Oriented Software Construction that a program is not a model of the world but a model of some part of the world; "Reality is a cousin twice removed". At the same time, some principal limitations of OOP had been noted. For example, the Circle-ellipse problem is difficult to handle using OOP's concept of inheritance.
1541 HyperDesk Corp., Digital Equipment Corp., Sun Microsystems and Object
1644 1, SunOS, ULTRIX, Digital VAX
1645 VMS, Digital OpenVMS
1649 Digital Equipment Corporation.
directory
1575 list <directory> [match] (index a directory, pattern 'match' files)
2052 - Naming - network implementation of X.500 directory
2075 directory entries required for cross domain operation
2181 (ORB) and contains a directory and name service that provides more
docs
775 .8 docs can be found online from the Rational home page, http:
1578 list docs
1579 get docs
1581 get docs
1590 list docs
domf
1654 Full implementation of the OMG CORBA 1.1 Object Request Broker. Also DOMF.
1774 Management Facility (DOMF), object services, developers' and administrative
1775 tools, and sample applications. HP's DOMF provides a location-transparent
1781 In addition, HP is working with IBM to integrate HP's DOMF with IBM's
1819 HP's DOMF includes the object request broker, interface- definition-
dur
2578 available by anonymous ftp from vega.dur.ac.uk as
2601 This paper is available by anonymous ftp from vega.dur.ac.uk in
2613 This paper is available by anonymous ftp from vega.dur.ac.uk in
2624 This paper is available by anonymous ftp from vega.dur.ac.uk in
2635 This paper is available by anonymous ftp from vega.dur.ac.uk in
earlier
10 Objects as a formal concept in programming were introduced in the 1960s in Simula 67, a major revision of Simula I, a programming language designed for discrete event simulation, created by Ole-Johan Dahl and Kristen Nygaard of the Norwegian Computing Center in Oslo. Simula 67 was influenced by SIMSCRIPT and Hoare's proposed "record classes". Simula introduced the notion of classes and instances or objects (as well as subclasses, virtual methods, coroutines, and discrete event simulation) as part of an explicit programming paradigm. The language also used automatic garbage collection that had been invented earlier for the functional programming language Lisp. Simula was used for physical modeling, such as models to study and improve the movement of ships and their content through cargo ports. The ideas of Simula 67 influenced many later languages, including Smalltalk, derivatives of LISP (CLOS), Object Pascal, and C++.
14 At ETH Z?rich, Niklaus Wirth and his colleagues had also been investigating such topics as data abstraction and modular programming (although this had been in common use in the 1960s or earlier). Modula-2 (1978) included both, and their succeeding design, Oberon, included a distinctive approach to object orientation, classes, and such. The approach is unlike Smalltalk, and very unlike C++.
54 ECMAScript language. JavaScript is perhaps the best known prototype- based programming language, which employs cloning from prototypes rather than inheriting from a class. Another scripting language that takes this approach is Lua. Earlier versions of ActionScript (a partial superset of the ECMA-262 R3, otherwise known as ECMAScript) also used a prototype-based object model. Later versions of ActionScript incorporate a combination of classification and prototype-based object models based largely on the currently incomplete ECMA-262 R4 specification, which has its roots in an early JavaScript 2 Proposal. Microsoft's JScript.NET also includes a mash-up of object models based on the same proposal, and is also a superset of the ECMA-262 R3 specification.
443 the earlier flavors. C++ declares an error iff a conflict arises, but a
759 [Yourdon 92] provides a critique, although may only refer to their earlier
elements
2 In the domain of object-oriented programming an object is usually taken to mean an ephemeral compilation of attributes (object elements) and behaviors (methods or subroutines) encapsulating an entity. In this way, while primitive or simple data types are still just single pieces of information, object-oriented objects are complex types that have multiple pieces of information and specific properties (or attributes). Instead of merely being assigned a value, (like int =10), objects have to be "constructed". In the real world, if a Ford Focus is an "object" - an instance of the car class, its physical properties and its function to drive would have been individually specified. Once the properties of the Ford Focus "object" had been specified into the form of the car class, it can be endlessly copied to create identical objects that look and function in just the same way. As an alternative example, animal is a superclass of primate and primate is a superclass of human. Individuals such as Joe Bloggs or John Doe would be particular examples or 'objects' of the human class, and consequently possess all the characteristics of the human class (and of the primate and animal superclasses as well).
47 Languages designed mainly for OO programming, but with some procedural elements. Examples: C++, C#, VB.NET, Java, Python.
57 Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1995 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, sometimes casually called the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. As of April 2007, the book was in its 36th printing.
569 [Booch 94, 2.2] proposes 7 "Elements of the Object Model"; 4 major and 3 minor:
858 Dion, R., "Elements of a Process Improvement Program," IEEE Software, July
entire
78 Joe Armstrong, the principal inventor of Erlang, is quoted as saying "The problem with object-oriented languages is they've got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle."
79 Richard Mansfield, author and former editor of COMPUTE! magazine, states that "like countless other intellectual fads over the years ("relevance", communism, "modernism", and so on—history is littered with them), OOP will be with us until eventually reality asserts itself. But considering how OOP currently pervades both universities and workplaces, OOP may well prove to be a durable delusion. Entire generations of indoctrinated programmers continue to march out of the academy, committed to OOP and nothing but OOP for the rest of their lives."[38] He also is quoted as saying "OOP is to writing a program, what going through airport security is to flying".
874 modeling entire organizations or a large part of them, with the information
1791 our entire company on it," said Richard Tanler, president and chief
2356 Program components frequently need knowledge of an entire program to
execution
967 fast running execution, but in a "true polymorphic system", only a single
2380 3. Message Passing Leads to Dynamic Execution Paths
2382 execution to make a compile-time determination of the last user of an
2387 clear order of execution. Other dynam ic control structures, such as
2611 execution of test cases for OOP. These tools assume a
facilities
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
1332 interactive user interface facilities, as found in a fully supported OODBMS.
1527 4) the Common Facilities will comprise facilities which are useful in
2662 Cantata provides comprehensive facilities for all forms of
float
628 +(int, float)
631 +(float, complex)
632 +(float, real)
633 +(float, float)
framework
1514 frameworks; an abstract framework for object-oriented systems; a set
1921 specification to provide a SMART communication framework allowing
1924 proven communication framework that links thousands of nodes.
2095 Cooperative Framework implementations on supported platforms
2573 Smith, M. D. and D. J. Robson, " A Framework for Testing Object-Oriented
fundamental
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
18 A survey by Deborah J. Armstrong of nearly 40 years of computing literature identified a number of "quarks", or fundamental concepts, found in the strong majority of definitions of OOP.
20 Benjamin C. Pierce and some other researchers view as futile any attempt to distill OOP to a minimal set of features. He nonetheless identifies fundamental features that support the OOP programming style in most object-oriented languages:
76 Alexander Stepanov suggested that OOP provides a mathematically-limited viewpoint and called it "almost as much of a hoax as Artificial Intelligence. I have yet to see an interesting piece of code that comes from these OO people. In a sense, I am unfair to AI: I learned a lot of stuff from the MIT AI Lab crowd, they have done some really fundamental work....".
1218 many instantiations such as a Stack of ints, a Stack of any fundamental
graphical
9 An object-oriented program may thus be viewed as a collection of interacting objects, as opposed to the conventional model, in which a program is seen as a list of tasks (subroutines) to perform. In OOP, each object is capable of receiving messages, processing data, and sending messages to other objects. Each object can be viewed as an independent "machine" with a distinct role or responsibility. The actions (or "methods") on these objects. The terms "objects" and "oriented" in something like the modern sense of object- oriented programming seem to make their first appearance at MIT in the late 1950s and early 1960s. In the environment of the artificial intelligence group, as early as 1960, "object" could refer to identified items (LISP atoms) with properties (attributes); Alan Kay was later to cite a detailed understanding of LISP internals as a strong influence on his thinking in 1966.[3] Another early MIT example was Sketchpad created by Ivan Sutherland in 1960-61; in the glossary of the 1963 technical report based on his dissertation about Sketchpad, Sutherland defined notions of "object" and "instance" (with the class concept covered by "master" or "definition"), albeit specialized to graphical interaction. Also, an MIT ALGOL version, AED-0, linked data structures ("plexes", in that dialect) directly with procedures, prefiguring what were later termed "messages", "methods" and "member functions".
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
883 including classes, inheritance, a high-powered graphical environment and a
1084 many kinds of objects such as text and graphical objects, multiple-polymorphism
2681 *Graphical test coverage to highlight any code not executed during test runs
handling
3 "Objects" are the foundation of object-oriented programming, and are fundamental data types in object-oriented programming languages. These languages provide extensive syntactic and semantic support for object handling, including a hierarchical type system, special notation for declaring and calling methods, and facilities for hiding selected fields from client programmers. However, objects and object-oriented programming can be implemented in any language.
663 handling, like C++ friends, usually by allowing representation details of more
1520 handling distribution of messages between application objects in
1543 application request handling software "bus."
2210 - Platform independent time services and exception handling
hewlett-packard
1540 from a joint proposal (named "CORBA") of Hewlett-Packard, NCR Corp.,
1655 Hewlett-Packard
1741 PALO ALTO, Calif.--(BUSINESS WIRE) via First! -- Hewlett-Packard Company
1836 Hewlett-Packard Company is an international manufacturer of measurement
2501 Fiedler, Steven P., "Object-Oriented Unit Testing", Hewlett-Packard
hyperdesk
1541 HyperDesk Corp., Digital Equipment Corp., Sun Microsystems and Object
1660 > HyperDesk (Westborough MA) HD-DOMS, rich_fraser@hyperdesk.com
1663 API only), NetWare (planned, Novell owns part of HyperDesk).
1725 HD-DOMS (HyperDesk Distributed Object Management System). A
identifying
107 and on identifying objects: "What are the *things* in this problem? Most of
110 covers "Identifying Key Abstractions" for objects and classes based on an
112 to identifying objects through use-cases (scenarios), leading to a use-case
706 "In OOA, we seek to model the world by identifying the classes and objects
735 "The process of identifying, collecting, organizing, and representing the
idl
1371 Ouverture Project (ESPRIT funded OMG IDL defines inter-module interfaces)
1669 Object RPC compatible with OMG CORBA 1.2 spec (will compile OMG IDL and
1733 mapping for IDL to the OMG recently.
2088 Languages used for IDL mapping - IDL bindings for C, (or
inherit
448 several classes. In classical systems without MI, a class which should inherit
552 - Types may inherit attributes from supertypes.
995 more than required. Since derived classes can inherit structure and behavior
1166 used for assignment compatibility forcing an assigned object to inherit
1193 to inherit from them, providing a subclass polymorphism facility, and ACs can
integrated
875 processing system and software products development as integrated components.
1604 integrated software systems. These systems should be built using
1749 integrated, desktop access to enterprise-wide information and resources in
1767 integrated set of services that can be used separately or together to
2026 Cooperative Frameworks consists of an integrated suite of
international
1456 International Conference on System Sciences (HICSS) (IEEE Computer Society
1504 The Object Management Group (OMG) is an international software industry
1836 Hewlett-Packard Company is an international manufacturer of measurement
2515 International Conference on Software Engineering, May, 1992,
2584 Problems of Validation", Proceedings of the 6th International
knowledge
737 their development histories, knowledge captured from domain experts,
1093 This removes the spread of knowledge of specific classes throughout a system,
1195 spreading knowledge of classes throughout a system, which is a high priority
2356 Program components frequently need knowledge of an entire program to
2373 low-level knowledge of how memory is structured. For example, programmers
leading
112 to identifying objects through use-cases (scenarios), leading to a use-case
713 "To us, analysis is the study of a problem domain, leading to a specification
834 leading to statistical (process) control and sustained improvement. Watts S.
1226 disadvantage when causing dynamic compilation (leading to a time
2687 *Integration with leading programming tools for maximum productivity gains
managed
6 An object-oriented program will usually contain different types of objects, each type corresponding to a particular kind of complex data to be managed or perhaps to a real-world object or concept such as a bank account, a hockey player, or a bulldozer. A program might well contain multiple copies of each type of object, one for each of the real-world objects the program is dealing with. For instance, there could be one bank account object for each real-world account at a particular bank. Each copy of the bank account object would be alike in the methods it offers for manipulating or reading its data, but the data inside each object would differ reflecting the different history of each account.
842 Level 4: Managed: A measurable basis for all improvements to the process.
2392 manually managed components and libraries often use incompatible memory
2418 their manually managed brethren. [3] In fact, multi-media programmers
2423 manually managed programs. Finally, garbage collection can be mixed with
messaging
1 Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, messaging, modularity, polymorphism, and inheritance. Many modern programming languages now support OOP, at least as an option. In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. (With the later introduction of object-oriented programming the same word, "object", refers to a particular instance of a class)
13 Object-oriented programming developed as the dominant programming methodology in the early and mid 1990s when programming languages supporting the techniques became widely available. These included Visual FoxPro 3.0, C++[citation needed], and Delphi[citation needed]. Its dominance was further enhanced by the rising popularity of graphical user interfaces, which rely heavily upon object-oriented programming techniques. An example of a closely related dynamic GUI library and OOP language can be found in the Cocoa frameworks on Mac OS X, written in Objective-C, an object-oriented, dynamic messaging extension to C based on Smalltalk. OOP toolkits also enhanced the popularity of event-driven programming (although this concept is not limited to OOP). Some[who?] feel that association with GUIs (real or perceived) was what propelled OOP into the programming mainstream.
644 ignoring the inherent type of parameters in messaging. Double dispatch is