Backus–Naur Form

lastmod 2018-08-17created 2014-09-257 edits

Backus–Naur form, abbreviated BNF, is a notation created to express context-free grammars. It is named after John Backus and Peter Naur.

About

Backus-Naur form (BNF) was the first metalanguage for defining programming languages. It was first introduced by John Backus in 1959 to describe the syntax of the ALGOL 58 language, and was enhanced by Peter Naur and used to define ALGOL 60. BNF expresses rules using metasymbols such as < > for syntactic elements, ∥ for a choice between alternatives, and ::= meaning that the left-hand side is defined by the right-hand side. BNF was originally "Backus normal form", but it was changed to its present name to include Peter Naur's name.

See also

• Formal language

Favorite site

• RFC 5234
• Wikipedia (en) description of BNF
• BNF (Backus-Naur form)
• BNF Converter Tutorial ¹

References