peg-3-pegGrammar.peg

hexDigit          <- [0123456789abcdefABCDEF]
escapedCharacter  <- '\\' ([abfnrtv0\\"'[\]] / ('u' hexDigit hexDigit hexDigit hexDigit))
safeCharacter     <- escapedCharacter / (!["\\\n] <anychar>)
oneofCharacter    <- escapedCharacter / (![\\\]] <anychar>)
terminalUnicode   <- '{' ( "Lu" / "Ll" / "Lt" / "Lm" / "Lo" /  "Mn" / "Mc" / "Me" / "Nd" / "Nl" / "No" / "Pc" / "Pd" / 
                           "Ps" / "Pe" / "Pi" / "Pf" / "Po" / "Sm" / "Sc" / "Sk" / "So" / "Zs" / "Zl" / "Zp" / "Cc" / 
                           "Cf" / "Cs" / "Co" / "Cn" ) '}'
terminalOneOf     <- '[' oneofCharacter+ ']'
terminalCharacter <- '\'' safeCharacter '\''
terminalWord      <- '\"' safeCharacter+ '\"'
terminal          <- terminalWord / terminalCharacter / terminalOneOf / terminalUnicode / "<anychar>" / "<epsilon>"
space             <- [ \t\r\n]+
name              <- ({Lu} / {Ll} / '-') ({Lu} / {Ll} / {Nd} / [_-])* 
nonterminal       <- name
atom              <- terminal / nonterminal / ('(' space? expr space? ')')
unary             <- ([!&] unary) / (atom [*+?])?
sequence          <- unary (space unary)*
choice            <- sequence (space? '/' space? sequence)*
expr              <- choice
codechar          <- (![{}\] <anychar>) / ('\\' [{}\\]) / ('{' codechar* '}')
codeblock         <- '{' codechar* '}'
rule              <- name space? "<-" space? expr space? codeblock? space? <epsilon>