| A syntax specification similar to EBNF.
This semantic is used to build a Parser with Lexer from a textual EBNF syntax specification.
The semantics of ".." is the description of the set between leading and trailing character.
The leading must be the one with the lower UNICODE value.
The semantics of "-" is intersection. When specifiying chars - comment - stringdef this means
all chars but not comments or stringdef, i.e. stringdef is not subtracted
from comment but from chars!
TODO: think over repeat number symbol: parser AND lexer would need this.
Better define this by written symbols like "a ::= b b b b;"? But what to do on hundred "b"?
author:
(c) 2002 Fritz Ritzberger | 