Syntax diagram: Difference between revisions

Revision as of 21:57, 21 January 2019

Revision as of 09:27, 13 October 2019

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We use arithmetic expressions as an example. First we provide a simplified BNF grammar:

<source lang="bnf">

<expression> ::= <term> | <expressionterm> "+" <termexpression>

<term> ::= <factor> | <termfactor> "*" <factorterm>

<factor> ::= <constant> | <variable> | "(" <expression> ")"

<variable> ::= "x" | "y" | "z"

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This grammar can also be expressed in [[EBNF]]:

<source lang="ebnf">

expression = term | expression, [ "+" , termexpression ];

term = factor | term, [ "*" , factorterm ];

factor = constant | variable | "(" , expression , ")";

variable = "x" | "y" | "z";

constant = digit , { digit };

digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";