Language of description of format of document

A language of description of format of document is a language making it possible to define a set of rules and constraints which will be used to know if a Instance of Document is valid compared to this same set of rules and constraints.

Examples

For example, if one invents a format whose main feature is to specify the constraints compared to the size of the file that we try to categorize (validates or not validates). One will use a Syntaxe near to mathematical syntax , by defining one or more equations checked by the variable TailleFichier: TailleFichier = 3 Thus a file containing the word “not” which makes three letters in ASCII is a valid file compared to this set of rules.

Extensions

A language of description of format is not necessarily final, in the direction where, it can be supplemented to provide other rules, making it possible to categorize more finely.

If one defines a whole of rule has to say if a document is an authority of has . It is enough to add a whole of rule B , noncontradictory with that of has , to create a Under-language has , checking has and B .

Binary files

The textual files

Syntax BNF (for Backus Naur Form)

See the article: Form of Backus-Naur.

Marked out languages

Family SGML

In SGML, there are three levels of description of a document:

  • the language of definition of the Syntaxe concretes (which makes it possible to specify the characters used to determine the openings and closings of beacon for example)
  • the language of definition of the Abstract syntax (which makes it possible to define DTD SGML)
  • the DTD SGML which makes it possible to define valid authorities of documents compared to this DTD
These are the three levels which made SGML, a standard very difficult to perceive and to implement.

The derived family: XML

In XML, one employs for example the language of description of format of document XML Schema. This language also allows the validation of documents (see DSDL). XML Schema is employed within the framework of the Registre UDDI.

Languages of description of texts

roff

HTML

Latex

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