-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) => "alternatives"
-
-sequence ::= es
- > es ws ^"/" e
-es ::= e %% (w**)
-
-ss ::= es | es ^"/" e /ws
-
-conjuncts ::= rewrite
- | rewrite ^"&" e%%ws /ws
- | rewrite ^"&~" e%%ws /ws
-
-rewrite ::= sequence /ws => "rewrite"
- | sequence ^"=>" word /ws
- | sequence ^"=>" quoted /ws
- | sequence "=>" "()" /ws => "wrap"
-
-ec ::= [~\-\]\\\~]
- | escaped
-
-range ::= ec => "range0"
- | ec ^"-" ec => "range1"
-
-e ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" alternatives "}" /ws
- | "[" (range*) "]" => "range"
- | "[~" (range*) "]" => "rangex"
- | e ^"%%" e /ws
- | e ^"$$" e /ws
- | e ^"+/" e /ws
- | e ^"*/" e /ws
- | e ^"?" /ws
- | e ^"~/~" /ws
-
- | e ^"-" e /ws
-
- | ^"!" e /ws
- | "^" quoted /ws => "care"
- | ^"`" e /ws
- | e ^"#" /ws
- | quoted => "literal"
-
- | (e ws ^"**" > e ws ^"*")
- | (e ws ^"++" > e ws ^"+")
-
- | "(" word ^")" /ws
- > ^"(" alternatives ")" /ws
-
-w !::= " "
- | "//" ([~\n]*) "\n"
- | "\n"
- | "\r"
-an ::= [a-zA-Z0-9_]
-word ::= an++ => "sify"
-quoted ::= "\"" (([~\"\\] | escaped)*) "\"" => "sify"
+s ::= !ws Grammar ws => "gram"
+Grammar ::= NonTerminal +/ ws => "grammar"
+NonTerminal ::= word ^"::=" RHS /ws
+
+RHS ::= (Conjuncts +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
+
+Conjuncts ::= Sequence
+ | Sequence ^"&" Elements /ws
+ | Sequence ^"&~" Elements /ws
+Elements ::= e*/ws
+
+PreSequence ::= Elements => "ps"
+ | PreSequence !wp ^"/" !ws e
+ | PreSequence ^"->" e /ws
+ | (Quoted|word) ^"::" PreSequence /ws
+ | PreSequence ^"=>" ("[]"|"()"|word|Quoted) /ws
+Sequence ::= PreSequence => "psx"
+
+ec ::= ~[\-\]\\]
+ | escaped
+
+Range ::= ec => "range"
+ | ec ^"-" ec
+
+e ::=
+ (Quoted|word) ^":" 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
+ | e ^"?" /ws
+ | ^"^" Quoted /ws
+
+ | "(" word ^")" /ws
+ > ^"(" RHS ")" /ws
+ | ^"~" e
+
+word ::= [a-zA-Z0-9_]++
+Quoted ::= "\"" ((~[\"\\] | escaped)+) "\""
+ | "\"\"" => ""