Grammar

A grammar is of the form:

Rule ::= Head "->" Prod [ ":" Prod ] [ Feat ] [ "#" Comment ]
Prod ::= ( Terminal | NonTerminal [ "-" Suffix ] [ FParam ] )* [ "{" Cost "}" ] 
Feat ::= "[" [ Name "=" Value ( "," Name "=" Value )* ] "]"
FParam ::= "(" [ Name [ "=" Value ] ( "," Name [ "=" Value ] )* ")"

where lexical symbols are:

• Terminal : Words starting with lowercase or -, containing alphabetics and - and ' or any characters between double quotes
• NonTerminal : Words starting with uppercase, containing alphanumerics and _ optionally ending with '
• Suffix, Name, Value : Words containing alphanumerics
• Cost : Integer

White space is ignored except between a NonTerminal and its parameters (e.g S -> A() is ok, but S-> A () is not ok). Start symbol is S, your grammar should derive from this. Internally S' is used as pre-start symbol and should not be used. Whitespace-only and/or comment-only lines are ignored