BNF and EBNF What is BNF? It stands for Backus-Naur Form It is a playal, mathematical style to specify context-free grammars It is precise and unambiguous Before BNF, assemblage specified programming languages ambiguously, i.e., with English How did BNF come round? crapper Backus presented a unused notation containing most of the elements of BNF at a UNESCO conference His show was about Algol 58 Peter Naur replete this report and found that he and Backus interpreted Algol differently He valued even more precision So he created what we now play as BNF for Algol 60 Thus BNF was first of all published in Algol 60 Report Who was commode Backus? Backus invented FORTRAN (FORMula TRANslator), the first high-altitude language ever, circa 1954 Major influence on the invention of functional programming in 1970s Won the 1977 Turing realize for BNF and FORTRAN Who was Peter Naur? Danish astronomer turned computer scientist Born in 1928; picture on left wing is from 1968 A Bit more History BNF originally stood for Backus everyday Form In 1964, Donald Knuth wrote a letter published in communication theory of the ACM in which he suggests it stand for Backus-Naur radiation diagram instead This was for two reasons: To recognize Naurs contribution BNF is not technically a normal form; this would suggest that there would be only one correct way of indite a grammar What does BNF look convertible?
Like this: ::= | ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 ::= means is defined as (some variants use := instead) | means or Angle brackets mean a nonterminal Symbols without angle brackets are terminals to a greater extent BNF Examples ::= while ( ) ::= = ::= | ::= | BNF for Expressions ::= + | - | ::= * | / | ::= ^ | ::= | ::= ( ) | | Origin of EBNF Stands for prolonged Backus-Naur Form After BNF appeared with Algol 60, oodles of...If you want to get a full essay, order it on our website:
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