s ::= ws grammar ws => "gram" ws !::= 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" psx ::= ps > ps ^"/" e /ws sequence ::= psx | psx ^"=>" (word|quoted) /ws ec ::= [~\-\]\\\~] | escaped range ::= ec => "range" | ec ^"-" ec e ::= word => "nonTerminal" | quoted => "literal" | ^"()" | ^"{" sequence "}" /ws | ^"[" range* "]" | ^"[~" range* "]" | (e ws ^"**" > e ws ^"*") | e ^"*/" e /ws | (e ws ^"++" > e ws ^"+") | e ^"+/" e /ws | e ^"?" /ws | "(" word ^")" /ws > ^"(" alternatives ")" /ws w !::= " " | "//" ([~\n]*) "\n" | "\n" | "\r" word ::= [a-zA-Z0-9_]++ quoted ::= "\"" (([~\"\\] | escaped)+) "\"" | "\"\"" => "" escaped ::= "\\n" => "\n" | "\\r" => "\r" | "\\" [~nr]