s ::= ws 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 ^"=>" (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]