-s ::= ws grammar ws => "gram"
-ws !::= w**
+s ::= grammar ws => "gram"
+ws !::= w** | w** "//" (~[\n]*) "\n" ws
+wp !::= w++
grammar ::= r +/ ws => "grammar"
r ::= word ^"::=" alternatives /ws
| sequence ^"&" e*/ws /ws
| sequence ^"&~" e*/ws /ws
-ps ::= e*/ws => "ps"
- | (e+/ws ws)? "^" quoted (ws e+/ws)? => "ps2"
-psx ::= ps
- > ps ^"/" e /ws
-sequence ::= psx
- | psx ^"=>" (word|quoted) /ws
-
-ec ::= [~\-\]\\\~]
+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"
| ^"()"
| ^"{" sequence "}" /ws
| ^"[" range* "]"
- | ^"[~" range* "]"
- | (e ws ^"**" > e ws ^"*")
- | e ^"*/" e /ws
- | (e ws ^"++" > e ws ^"+")
- | e ^"+/" e /ws
+ | (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"
word ::= [a-zA-Z0-9_]++
-quoted ::= "\"" (([~\"\\] | escaped)+) "\""
+quoted ::= "\"" ((~[\"\\] | escaped)+) "\""
| "\"\"" => ""
escaped ::= "\\n" => "\n"
| "\\r" => "\r"
- | "\\" [~nr]
+ | "\\" ~[nr]