CodeMirror

PEG.js Mode

/* * Classic example grammar, which recognizes simple arithmetic expressions like * "2*(3+4)". The parser generated from this grammar then computes their value. */ start = additive additive = left:multiplicative "+" right:additive { return left + right; } / multiplicative multiplicative = left:primary "*" right:multiplicative { return left * right; } / primary primary = integer / "(" additive:additive ")" { return additive; } integer "integer" = digits:[0-9]+ { return parseInt(digits.join(""), 10); } letter = [a-z]+

The PEG.js Mode

Created by Forbes Lindesay.