-s ::= w* Grammar w* => "gram"
-Grammar ::= R+ => "grammar"
-R ::= word ^"::=" Alternatives
- | word ^"!::=" Alternatives
-
-ec ::= [~\]\\\-\~] | escaped
-
-Alternatives ::= EquiAlt +/ ">"
-EquiAlt ::= Conjuncts +/ "|" => "alternatives"
-
-Sequence ::= E+ ^"/" E
- > E+
-
-Conjuncts ::= Rewrite
- | Rewrite ^"&" Sequence
- | Rewrite ^"&~" Sequence
-
-Rewrite ::= Sequence => "rewrite"
- | Sequence ^"=>" word
- | Sequence ^"=>" quoted
- | Sequence "=>" "()" => "wrap"
-
-range ::= ec => "range0" | ec ^"-" ec => "range0"
-E ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" Alternatives "}"
- | "[" [\~]? range* "]" => "range"
- | E ^"*/" E
- | E ^"+/" E
- | E ^"?"
- | E ^"~/~"
-
- | E ^"-" E
-
- | ^"!" E
- | "^" quoted => "care"
- | ^"`" E
- | E ^"#"
+s ::= 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 ^"**" > E ^"*")
- | (E ^"++" > E ^"+")
+ | (e ^"++" /ws > e ^"+" /ws)
+ | (e ^"++/" e /ws > e ^"+/" e /ws)
+ | (e ^"**" /ws > e ^"*" /ws)
+ | (e ^"**/" e /ws > e ^"*/" e /ws)
+ | e ^"?" /ws
- | "(" word ^")"
- > ^"(" Alternatives ")"
+ | "(" word ^")" /ws
+ > ^"(" alternatives ")" /ws
+ | ^"~" e
w !::= " "
- | "//" [~\n]* "\n"
| "\n"
| "\r"
-an ::= [a-zA-Z0-9_]
-word ::= an++ => "sify"
-quoted ::= "\"" ([~\"\\] | escaped)* "\"" => "sify"
+word ::= [a-zA-Z0-9_]++
+quoted ::= "\"" ((~[\"\\] | escaped)+) "\""
+ | "\"\"" => ""
escaped ::= "\\n" => "\n"
| "\\r" => "\r"
- | "\\" [~nr]
+ | "\\" ~[nr]
+
+