Cosa (chi) è Extended Backus-Naur Form - definizione

FAMILY OF METASYNTAX NOTATIONS, ANY OF WHICH CAN BE USED TO EXPRESS A CONTEXT-FREE GRAMMAR

EBNF; Extended Backus-Naur Form; Extended Backus Naur Form; Extended Backus Naur form; Ebnf; ISO 14977; Extended Backus-Naur form; Extended BNF; Extended Backus–Naur Form; ISO/IEC 14977

Extended Backus–Naur form

In computer science, extended Backus–Naur form (EBNF) is a family of metasyntax notations, any of which can be used to express a context-free grammar. EBNF is used to make a formal description of a formal language such as a computer programming language.

https://en.wikipedia.org/wiki/Extended_Backus–Naur_form

Extended Backus-Naur Form

<language> Any variation on the basic Backus-Naur Form (BNF) meta-syntax notation with (some of) the following additional constructs: square brackets "[..]" surrounding optional items, suffix "*" for Kleene closure (a sequence of zero or more of an item), suffix "+" for one or more of an item, curly brackets enclosing a list of alternatives, and super/subscripts indicating between n and m occurrences. All these constructs can be expressed in plain BNF using extra productions and have been added for readability and succinctness. (1995-04-28)

EBNF

<language> Extended Backus-Naur Form.

Wikipedia

Extended Backus–Naur form

In computer science, extended Backus–Naur form (EBNF) is a family of metasyntax notations, any of which can be used to express a context-free grammar. EBNF is used to make a formal description of a formal language such as a computer programming language. They are extensions of the basic Backus–Naur form (BNF) metasyntax notation.

The earliest EBNF was developed by Niklaus Wirth, incorporating some of the concepts (with a different syntax and notation) from Wirth syntax notation. Today, many variants of EBNF are in use. The International Organization for Standardization adopted an EBNF Standard, ISO/IEC 14977, in 1996. According to Zaytsev, however, this standard "only ended up adding yet another three dialects to the chaos" and, after noting its lack of success, also notes that the ISO EBNF is not even used in all ISO standards. Wheeler argues against using the ISO standard when using an EBNF and recommends considering alternative EBNF notations such as the one from the W3C Extensible Markup Language (XML) 1.0 (Fifth Edition).

This article uses EBNF as specified by the ISO for examples applying to all EBNFs. Other EBNF variants use somewhat different syntactic conventions.

https://en.wikipedia.org/wiki/Extended Backus–Naur form