-s ::= ws grammar ws => "gram"
-ws !::= w**
+s ::= grammar ws => "gram"
+ws !::= w** | w** "//" (~[\n]*) "\n" ws
+wp !::= w++
grammar ::= r +/ ws => "grammar"
+
r ::= word ^"::=" alternatives /ws
| word ^"!::=" alternatives /ws
-alternatives ::= equiAlt +/ (ws ">" ws)
-equiAlt ::= conjuncts +/ (ws "|" ws)
-
-conjuncts ::= rewrite
- | rewrite ^"&" e*/ws /ws
- | rewrite ^"&~" e*/ws /ws
-
-sequence ::= e*/ws
- (ws "/" e)?
- (ws "=>" ws (word|quoted))? => "seq"
-
-rewrite ::= sequence
-
-ec ::= [~\-\]\\\~]
+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"
- | [(][)] => "epsilon"
- | ^"{" alternatives "}" /ws
- | ^"[" (range*) "]"
- | ^"[~" (range*) "]"
- | ^"^" quoted /ws
- | ^"!" e /ws
-
- | (e ws ^"**" > e ws ^"*")
- | e ^"*/" e /ws
- | (e ws ^"++" > e ws ^"+")
- | e ^"+/" e /ws
- | e ^"?" /ws
-
+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
+ | "(" word ^")" /ws
+ > ^"(" alternatives ")" /ws
+ | ^"~" e
w !::= " "
- | "//" ([~\n]*) "\n"
| "\n"
| "\r"
word ::= [a-zA-Z0-9_]++
-quoted ::= "\"" (([~\"\\] | escaped)+) "\""
+quoted ::= "\"" ((~[\"\\] | escaped)+) "\""
| "\"\"" => ""
escaped ::= "\\n" => "\n"
| "\\r" => "\r"
- | "\\" [~nr]
+ | "\\" ~[nr]