1 s ::= ws grammar ws => "gram"
3 grammar ::= r +/ ws => "grammar"
4 r ::= word ^"::=" alternatives /ws
5 | word ^"!::=" alternatives /ws
7 alternatives ::= equiAlt +/ (ws ">" ws)
8 equiAlt ::= conjuncts +/ (ws "|" ws)
10 conjuncts ::= sequence
11 | sequence ^"&" e*/ws /ws
12 | sequence ^"&~" e*/ws /ws
16 (ws "=>" ws (word|quoted))? => "seq"
21 range ::= ec => "range"
24 e ::= word => "nonTerminal"
27 | ^"{" sequence "}" /ws
33 | (e ws ^"**" > e ws ^"*")
35 | (e ws ^"++" > e ws ^"+")
40 > ^"(" alternatives ")" /ws
46 word ::= [a-zA-Z0-9_]++
47 quoted ::= "\"" (([~\"\\] | escaped)+) "\""
49 escaped ::= "\\n" => "\n"