-s ::= w* Grammar w* => "gram"
-Grammar ::= R+ => "grammar"
-R ::= word ^"::=" Class+/gt
- | word ^"!::=" Class+/gt
-
-ec ::= [~\]\\\-\~] | escaped
-
-Class ::= Rewrite +/ "|" => "alternatives"
-
-Rewrite ::= Rewritex
- | Rewritex ^"&" E+
- | Rewritex ^"&~" E+
-
-Rewritex ::= E+ => "rewrite"
- | E+ ^"=>" word
- | E+ ^"=>" quoted
- | E+ "=>" "()" => "wrap"
-
-range ::= ec => "range0" | ec ^"-" ec => "range0"
-gt !::= ">"
-bar !::= "|"
-E ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" Class+/gt "}"
- | "[" [\~]? range* "]" => "range"
- | E ^"*/" E
- | E ^"+/" E
- | E ^"?"
- | E ^"~/~"
-
- | E ^"-" E
-
- | ^"!" E
- | "^" quoted => "care"
- | ^"`" E
- | E ^"#"
- | quoted => "literal"
-
- | (E ^"**" > E ^"*")
- | (E ^"++" > E ^"+")
-
- | "(" word ^")"
- > ^"(" Class+/gt ")"
+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"
+ | psx "=>" ^"[]" /ws
+ | psx ^"=>" (word|Quoted) /ws
+
+ec ::= ~[\-\]\\]
+ | escaped
+
+Range ::= ec => "range"
+ | ec ^"-" ec
+
+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
+ | ^"~" 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]
+
+