s ::= w* Grammar w* => "gram" Grammar ::= R+ => "grammar" R ::= word ^"::=" Class+/gt | word ^"!::=" Class+/gt ec ::= [~\]\\\-\~] | escaped Class ::= Rewrite +/ bar => "alternatives" Rewrite ::= Rewritex | Rewritex ^"&" E+ | Rewritex ^"&~" E+ Rewritex ::= E+ => "rewrite" | E+ ^"=>" word | E+ ^"=>" quoted | E+ "=>" "()" => "wrap" range ::= ec => "range0" | ec ^"-" ec => "range0" gt !::= ">" bar !::= "|" E ::= word => "nonTerminalY" | [(][)] => "epsilon" | ^"{" Class+/gt "}" | "[" [\~]? range* "]" => "range" | E ^"*/" E | E ^"+/" E | E ^"?" | E ^"~/~" | E ^"-" E | ^"!" E | "^" quoted => "care" | ^"`" E | E ^"#" | quoted => "literal" | (E ^"**" > E ^"*") | (E ^"++" > E ^"+") | "(" word ^")" > ^"(" Class+/gt ")" w !::= " " | "//" [~\n]* "\n" | "\n" | "\r" an ::= [a-zA-Z0-9_] word ::= an++ => "sify" quoted ::= "\"" ([~\"\\] | escaped)* "\"" => "sify" escaped ::= "\\n" => "\n" | "\\r" => "\r" | "\\" [~nr]