s ::= Grammar ws => "gram" ws !::= w** | w** "//" (~[\n]*) "\n" ws wp !::= w++ Grammar ::= r +/ ws => "grammar" r ::= word ^"::=" alternatives /ws | word ^"!::=" alternatives /ws alternatives ::= (Conjuncts +/ (ws "|" ws)) +/ (ws ">" ws) Conjuncts ::= Sequence | Sequence ^"&" e*/ws /ws | Sequence ^"&~" e*/ws /ws ps ::= e*/ws => "ps" | (e+/ws ws)? "^" Quoted (ws e+/ws)? => "ps2" psy ::= ps | ps wp ^"/" ws e psx ::= psy => "psy" | e "<-" psy /ws => "psyl" | psy "->" e /ws => "psyr" | e "<-" psy "->" e /ws => "psylr" Sequence ::= Quoted => "qprod" > psx | psx "=>" ^"[]" /ws | psx ^"=>" (word|Quoted) /ws ec ::= ~[\-\]\\] | escaped Range ::= ec => "range" | ec ^"-" ec e ::= word => "nonTerminal" | Quoted => "literal" | ^"()" | ^"{" Sequence "}" /ws | ^"[" Range* "]" | (e ^"++" /ws > e ^"+" /ws) | (e ^"++/" e /ws > e ^"+/" e /ws) | (e ^"**" /ws > e ^"*" /ws) | (e ^"**/" e /ws > e ^"*/" e /ws) | e ^"?" /ws | "(" word ^")" /ws > ^"(" alternatives ")" /ws | ^"~" e w !::= " " | "\n" | "\r" word ::= [a-zA-Z0-9_]++ Quoted ::= "\"" ((~[\"\\] | escaped)+) "\"" | "\"\"" => "" escaped ::= "\\n" => "\n" | "\\r" => "\r" | "\\" ~[nr]