2.2 Classification of the programming languages

At present there are thousand, if not tens and hundred thousand languages, dialects and their implementations. Moreover, new languages are daily born or dialects existing of the languages appear.

Almost any language is possible to examine as the improved version of any other language. It is sometimes very difficult draw a breakpoint link, where one language comes to an end and another starts. Take, for example, «LISP», which started as the separate language and has resulted in the total in the whole set of languages. Its dialects such as «Scheme» or «Common Lisp» have the large differences. Its variants such as «Kyoto Common Lisp» or «Allegro CL» and are identical, but can have some features, which make them incompatible.

The implementations are established for start-up on the concrete computer with a concrete operating system and can have additional properties. Some sequential invisible variations in implementation can result in small variations in the language.

Not always the name of the language can unambiguously identify it. Sometimes a language can undergo significant variations in the language without the change of the name. Sometimes only the name varies, and language remains same «IAL» in «ALGOL», and then in «ALGOL 58». And it happens, that one name is used for several different languages.

Usually it is difficult it happens to distinguish, that belongs to the characteristic of the language, and to its environment. For example, «SML» is described in some stages, at first the syntax of a nucleus, and then its expansions, that technically defines two various languages. The descriptions of some languages can omit such important features, as is the file inlet/lead-out as is not supposed use them without the standard library, in a case of C, for example, or without the environment of development as a whole, or because it makes the command language of any operating system or commercial product.

At the same time some languages are inherently extended as «Fort», and for them there is such plenty of such expansions as for «TeX», for example, that each such expansion is possible to consider as the separate language.

It often happens that a known manufacturer brings in expansions to the core language in the implementation, for example, «Turbo Pascal» or «Delphi» in implementations «of the Borland» corporation strongly differs from the out-of-date standard «ANSI». The same tendency it is especially visible in various implementations of «BASIC» or «Prolog». The implementations of «Basic» of one corporation can often strongly differ from each other, for example «Microsoft» has the following list of different from each other variants to a greater or lesser extent «Basic»: «Visual Basic», «Visual Basic for Applications», «Access Basic», «WordBasic», «TestBasic», «Basic PDS». Even the different implementations of such language as C can strongly differ from each other, so for example it is possible to consider «Turbo C» and «Microsoft C» as separate languages.

Often it can be so, that the language is an integral part of any commercial system. Some of them will be considered here.

During the classification of languages we can select the following types of languages: [17], [18].

3.2.1 S c r i p t l a n g u a g e s h a v e a r i s e n i n 1 9 6 0 s. Then there was an acute need for languages providing a program manager, differently speaking for, command languages of the tasks.

Belong to the commands, they are the Numerous command interpreters «CLI», so-called languages of batch processing and languages for construction of system command sheaths, vivid example - «sh», «csh» and their variations for «UNIX». As a rule, such languages are oriented not to interactive, and to the batch mode of processing, when the involvement of a man at the stage of execution is shown as zero and all works in continuous stream. These languages could not directly cooperate with an appropriate operating system, but also were supplied with a means of parsing of the programs and transformation of the data. With their help it was possible to establish various program filters used, in particular, in the pipeline of a system «UNIX». «Awk» is one of the known languages of such type for the first time appeared in «AT&T UNIX Version 7», and now is becoming a part of the standard «POSIX Command Language and Utilities». It is possible to attribute the mechanism of regular expressions, to key features of the language, which has found subsequently wide application in the environment universal script of languages, without which the analysis of the text is not so effective.

The programming languages

The description languages of documents

Figure 2 - Classification of the programming languages

Languages of this class were oriented also to processing of system events, generating the text and high level access to data bases. Here it is necessary to mark the «RPG» language. This time it before is successfully applied to creation of the reports from corporate DB operating mainly on mainframes «RPG/400» for computers «IBM AS/400».

Today «Rexx» is used most actively from languages of this class, it is created in research laboratories «IBM». On a kit it differs a little, from universal script of languages, however it is fulfilled as the classical block-structured procedural language and is intended mainly for integration and expansion of a multifunction of applications.

2.2.2 A p p l i e d s c r i p t l a n g u a g e s a p p e a r e d i n 1 9 8 0 s, i n e p o c h o f a p p e a r a n c e o f i n d u s t r i a l P Cs. Then there appeared a necessity of the tasks of interactive dialogue with an operating system, and also data access of spreadsheets and data bases. A distinctive feature of script languages of the given class is the orientation to a client part of the software.

The table 1 - Applied script languages

The name	Year of appearance	The developer of the language	Organization, where the language was created
HyperTalk	1986	-	Apple Computer
Visual Basic	1990	-	Microsoft
JavaScript	1994	-	Netscape Communications, Microsoft
CorelScript	1995	-	Corel
LotusScript	1995	-	Lotus Development
VBScript	1995	-	Microsoft
Pnuts	2001	Toyokazu Tomatsu	Sun Microsystems

Usage of object model in languages of the given class becomes already a norm, instead of exception. They still cannot be named as full languages of object-oriented programming; however they appreciably try to use convenience of the object approach.

Among applied script languages there is a variety for office programming, as «VBA» mostly selects «Visual Basic», including. «Visual Basic» is that most «boundary» language, which concerns to script, than to traditional faster. It influenced in many respects such class of languages, as applied script languages. Moreover, operation with the user's interface and embedding of program components «VBX», «OCX», «ActiveX» of steel hardly probable not by a visiting card of the given language. It is necessary to note, that in a course of evolution «VBA» has swallowed other specific languages, in particular «Word Basic» and «Excel Macro Language», having undertaken their tasks. Under its influence such languages, as «VBScript», special dialect of the language Visual Basic, oriented on creation of OLE-components and on operation were created within the framework of browsers and «LotusScript», some kind of analog of languages «VBA» and «CorelScript», intended for problem solving of automation of office in frameworks «Lotus Notes».

«JavaScript» stands especially in this number, becoming the standard in Internet - programming at implementation of a client part. Its prototype was the «LiveScript» language, being a part of the server «LiveWire» product of the «Netscape» company and originally built - in «Netscape Navigator 2.0». After appearance of the «Java» language of corporation «Sun Microsystems» it began to play a role of a self-sufficient deckhouse above this language, and his (its) name was replaced by «JavaScript». Dialects of this language is «Jscript» of corporation Microsoft and «ECMAScript».

«JavaScript» can be used at shaping of the program code of the tests input and outgoing control of the multimedia manual created on the basis of Internets - technologies.

We shall mention the experimental «Pnuts» language from the beginners in the given class of languages, which fundamental idea is to give of the scripts the most complete access to «Java API» within the framework. It can be used for the most different tasks, but, first of all for operation with the component software.

2.2.3 L a n g u a g e s o f s e c t o r i n g, o r t a g g e d l a n - g u a g e s, s t a n d a l i t t l e a t s o m e d i s t a n c e f r o m a t r u n k l i n e o f d e v e l o p m e n t o f s c r i p t l a n g u a g e s. The systems of macro processing, every possible macroprocessors, so popular in 1960s 1970s are closest for them. Their main distinctive feature - embedding of a special code as isolated «commands» - tags is direct in the normal texts. Such languages, as «Postscript» and «RTF» which are more often perceived simply as the special format of representation of documents. The tags are to use for the most different purposes: for separation of structure of the information from its contents, for embedding commands of formatting and even for the job of dynamic behaviour of interactive objects, built - in in the document.

The idea of separation of structure of the information from the contents has arisen long ago. The first realized decision became start-up of the project «GenCode». In September, 1967 William Tannicliff, the chairman of Committee under the composite decisions of association «Graphic Communications Association», has offered to draw a precise border between the contents and format of representation of the information. The chief of «GCA» Norman Sharpf receives the decision to begin implementation of the appropriate project «GenCode».

The table 2 - Languages of sectoring

The name	Year of appearance	The developer of the language	Organization, where the language was created
GML	1969	Charles Goldfarb	IBM
TeX	1979	Donald Knut	Stanford University
SGML	1986	-	ISO
HTML	1991	Tim Bernersly	CERN
CFML (Cold Fusion)	1995	-	Allaire
DHTML	1996	-	Microsoft, Netscape Communications
XML	1997	-	W3C
XHTML	2001	-	W3C

Under the influence «GenCode» in 1969 the American scientist Charles Goldfarb has headed operation of research group in «IBM», which purpose was the study of principles of the integrated information systems in the field of the legislation. A fruit of efforts of this collective, where also Edward Mosher and Raymond Lorry entered, became «GML» - generalized language of sectoring. It is the power language of sectoring «ISO 8879». «Sgmls» is «SGML» the analyzer, descendant «ARCSGML» of the analyzer written Charles Goldfarb. Puts out idle time, easy, line, «ASCII» representation «SGML» of structure «Element Structure Information Set». Is used for applications with control structures as «SGML». «SGML» is an important step in a direction of junction to separation of the information from its representation. Many decisions of this group have found application in various publishing systems of «IBM». On the base of «GML» and ideas of the system «Scribe», developed by Brian Raid, the International organization of the standardization of «ISO» has developed a meta-language «SGML», standard «ISO-8879:1986».

The most significant achievements are in the field of languages of sectoring of steel «TeX», ««HTML» and ««XML». The language has anticipated «TeX», developed in 1979 by Donald Knout, for three years «Postscript», created John Wornok in «Adobe» company which is intended for the exact description of the external form of documents with composition of arbitrary complexity. Unlike the low level of «Postscript», the language orients to «TeX» on operation of the users not having skills of programming. To be applied this language began most widely in the scientific environment, where the highest requirements to quality of construction of the formulas of complex structure are needed.

The «HTML» language, with which appearance concept «hypertext» became simple and ordinary, was established on the base of «SGML» by maximum simplification of its structure and properties. There is no meaning to describe it in detail: it is the fundamental language of representation of the information in the Internet - environment. For this reason the given programming language can be applied for creation of the multimedia project, as it enables to publish the given project by means of the Internet.

The meta-language «XML», created mostly by John Bosak, the chief of a workgroup «SGML ERB», also was grounded on «SGML», but for him it is a characteristic of more careful ratio to ideas of the grandparents, and he absolutely fulfils an other role, rather than «HTML». It is some kind of the language of transportation and intermediate data storage at the exchange by them between the diverse and distributed systems. On its base it is possible to spend many complex conversions of documents and textual information, and the main, thing is to store the given relational-outlines, including tunings and programming of components. It is truly the truth, does not prevent to use it and not absolutely on designation - for the job speakers of behaviour of every possible objects. In 2001 the audit «HTML» has appeared which has received the name of «XHTML», where the requirements «XML» were taken into account.

«Postscript» as the implementation of «Ghostscript» is the available «Postscript» as the interpreter with the possibility of review for many systems and many fonts. It is used under operating systems: «Unix», «MS DOS».

«CFML» and «DHTML» are the languages of sectoring directly intended for dynamic creation of Internets - pages and access to a DB. They are both expansions of «HTML», but «CFML» is only a commercial language of the «Allaire» company, not having other implementation, and «DHTML», arisen from «Dynamic HTML», is the result of the numerous compromises and competition of «Netscape» and of «Microsoft», which were summed up by a consortium of «W3C». The same «ASP» is as a matter of fact, the script on «VBScript», which is done on a server.