-s ::= !ws Grammar ws => "gram"
-Grammar ::= NonTerminal +/ ws => "grammar"
-NonTerminal ::= word ^"::=" RHS /ws
+// use 'a'-'z' or 'a-z' instead of [a-z]?
+// EOF token?
+// #include (with renaming?)
-RHS ::= (Conjuncts +/ (!ws "|" !ws)) +/ (!ws ">" !ws)
+s = ws! Grammar ws!
-Conjuncts ::= Sequence
- | Sequence ^"&" Elements /ws
- | Sequence ^"&~" Elements /ws
-Elements ::= e*/ws
+Grammar = Declaration +/ ws
-psy ::= Elements => "ps"
- | psy !wp ^"/" !ws e
- | psy ^"->" e /ws
- | psy ^"=>" ("[]"|"()"|word|Quoted) /ws
-Sequence ::= Quoted => "qprod"
- > psy => "psx"
+Declaration = NonTerminal
+ | ^"#import" ws! FileName (ws! "as" ws! Word)?
-ec ::= ~[\-\]\\]
+FileName = FileNameChar+ -> [\r\n ]
+FileNameChar = Space:: "\\ "
+ | ~[\r\n ]
+
+NonTerminal = Word "=" RHS /ws
+ | Word "*" ws! ^"=" ws! RHS
+ | Word "*/" Word ws! ^"=" ws! RHS
+
+RHS = (Sequence +/ (ws! "|" ws!)) +/ (ws! ">" ws!)
+
+Elements = e*/ws
+
+PreSequence = Elements
+ | (Quoted|Word) ^"::" PreSequence /ws
+ > PreSequence ^"/" e /ws
+ | PreSequence ^"->" e /ws
+
+Sequence = psx:: PreSequence
+ | Sequence ^"&" Elements /ws
+ | Sequence ^"&~" Elements /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
- | e ^"?" /ws
- | ^"^" Quoted /ws
-
- | "(" word ^")" /ws
- > ^"(" RHS ")" /ws
- | ^"~" 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++
+Range = ec
+ | ec "-" ec
+
+e = (Quoted|Word) ^":" e
+ > NonTerminalReference
+ | Literal
+ | ^"()"
+ | ^"{" PreSequence "}" /ws
+ | ^"[" Range* "]"
+ | e ^"++" /ws -> ~[/]
+ | e ^"+" /ws -> ~[+]
+ | e ^"++/" e /ws
+ | e ^"+/" e /ws
+ | e ^"**" /ws -> ~[/]
+ | e ^"*" /ws -> ~[*]
+ | e ^"**/" e /ws
+ | e ^"*/" e /ws
+ | e ^"!"
+ | e ^"?" /ws
+ | ^"^" Quoted
+ > ^"(" RHS ")" /ws
+ | ^"~" e
+
+NonTerminalReference = Word
+Literal = Quoted
+Word = [.a-zA-Z0-9_]++
+Quoted = "\"" ((~[\"\\] | escaped)+) "\""
+ | EmptyString
+ EmptyString = "\"\""
+
+escaped = "\n":: "\\n"
+ | "\r":: "\\r"
+ | "\\" ~[nr]
+
+w = " " | "\n" | "\r"
+ws = w**
+ | w** "//" (~[\n])*! "\n" ws!
+wp = w++