-s ::= ws grammar ws => "gram"
-ws !::= w**
-grammar ::= r $$ ws => "grammar"
+s ::= Grammar ws => "gram"
+ws !::= w** | w** "//" (~[\n]*) "\n" ws
+wp !::= w++
+Grammar ::= r +/ ws => "grammar"
+
r ::= word ^"::=" alternatives /ws
| word ^"!::=" alternatives /ws
-alternatives ::= equiAlt $$ (ws ">" ws)
-equiAlt ::= conjuncts $$ (ws "|" ws) => "alternatives"
-
-sequence ::= Es
- > Es ws ^"/" e
-Es ::= e %% (w**)
-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 ::= [~\-\]\\\~]
+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 "=>" ^"[]" /ws
+ | psx ^"=>" (word|Quoted) /ws
+
+ec ::= ~[\-\]\\]
| escaped
-range ::= ec => "range0"
- | ec ^"-" ec => "range1"
+Range ::= ec => "range"
+ | ec ^"-" ec
-e ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" alternatives "}" /ws
- | "[" ranges "]" => "range"
- | "[~" ranges "]" => "rangex"
- | 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 ::= word => "nonTerminal"
+ | Quoted => "literal"
+ | ^"()"
+ | ^"{" Sequence "}" /ws
+ | ^"[" Range* "]"
- | (e ws ^"**" > e ws ^"*")
- | (e ws ^"++" > e ws ^"+")
-
- | "(" word ^")" /ws
- > ^"(" alternatives ")" /ws
+ | (e ^"++" /ws > e ^"+" /ws)
+ | (e ^"++/" e /ws > e ^"+/" e /ws)
+ | (e ^"**" /ws > e ^"*" /ws)
+ | (e ^"**/" e /ws > e ^"*/" e /ws)
+ | e ^"?" /ws
-ranges ::= range*
+ | "(" 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]