View source for Backus–Naur Form

In [[computer science]], '''BNF''' ('''Backus Normal Form''' or '''Backus–Naur Form''') is one of the two main notation techniques for [[Context-free grammar|context-free grammars]].

== Description ==

[[Context-free grammar|Context-free grammars]] are often used to describe the [[Syntax (programming languages)|syntax]] of [[languages]] used in [[computing]], such as:

* [[Computer programming languages]]
* [[Document format|Document formats]]
* [[Instruction set|Instruction sets]]
* [[Communication protocol|Communication protocols]]

They are applied wherever exact descriptions of languages are needed. for instance in:

* Official language specifications
* Manuals
* Textbooks on [[programming language theory]]

== Extensions and variants ==

Many extensions and variants of the original Backus–Naur notation are used; some are exactly defined, including Extended Backus–Naur Form (EBNF) and Augmented Backus–Naur Form (ABNF).

== van Wijngaarden form==

The other main technique for writing context-free grammars is the [[Van Wijngaarden grammar|van Wijngaarden form]].

== See also ==

* [[Attribute grammar]]
* [[Computer science]]
* [[Formal grammar]]
* [[Van Wijngaarden grammar]]

== External links ==

* [https://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form Backus–Naur Form] @ Wikipedia

[[Category:Computer science]]