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