-s ::= ws grammar ws => "gram"
-ws !::= w**
-grammar ::= r+/ws => "grammar"
-r ::= word ^"::=" Alternatives /ws
- | word ^"!::=" Alternatives /ws
-
-ec ::= [~\]\\\-\~] | escaped
-
-Alternatives ::= EquiAlt +/ ">"
-EquiAlt ::= Conjuncts +/ "|" => "alternatives"
-
-sequence ::= Es
- > Es ^"/" E /ws
-Es ::= E+
-//es ::= E+/ws
-
-Conjuncts ::= rewrite
- | rewrite ^"&" sequence
- | rewrite ^"&~" sequence
-
-rewrite ::= sequence /ws => "rewrite"
- | sequence ^"=>" word /ws
- | sequence ^"=>" quoted /ws
- | sequence "=>" "()" /ws => "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 ^"#"
- | quoted => "literal"
-
- | (E ^"**" > E ^"*")
- | (E ^"++" > E ^"+")
-
- | "(" word ^")"
- > ^"(" Alternatives ")"
-
-w !::= " "
- | "//" [~\n]* "\n"
- | "\n"
- | "\r"
-an ::= [a-zA-Z0-9_]
-word ::= an++ => "sify"
-quoted ::= "\"" ([~\"\\] | escaped)* "\"" => "sify"
-escaped ::= "\\n" => "\n"
- | "\\r" => "\r"
- | "\\" [~nr]
+s = ws gram:Grammar ws
+Grammar = grammar:: NonTerminal +/ ws
+NonTerminal = word !wp ^"=" !wp RHS
+
+RHS = (Sequence +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
+
+Elements = e*/ws
+
+PreSequence = ps:: Elements
+ | PreSequence !wp ^"/" !ws e
+ | PreSequence ^"->" e /ws
+ | (Quoted|word) ^"::" PreSequence /ws
+
+Sequence = psx:: PreSequence
+ | Sequence !ws ^"&" !ws Elements
+ | Sequence !ws ^"&~" !ws Elements
+
+ec = ~[\-\]\\]
+ | escaped
+
+Range = range:: ec
+ | ec ^"-" ec
+
+e = (Quoted|word) ^":" e
+ > nonTerminal:: word
+ | literal:: Quoted
+ | ^"()"
+ | ^"{" 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
+ | e ^"?" /ws
+ | ^"^" Quoted
+ | "(" word ^")" /ws
+ > ^"(" RHS ")" /ws
+ | ^"~" e
+ > "^^":: "^" e
+
+word = [a-zA-Z0-9_]++
+Quoted = "\"" ((~[\"\\] | escaped)+) "\""
+ | "":: "\"\""
+escaped = "\n":: "\\n"
+ | "\r":: "\\r"
+ | "\\" ~[nr]
+
+
+w = " " | "\n" | "\r"
+ws = "()":: w**
+ | "()":: w** "//" ~[\n]* "\n" ws
+wp = w++