[antlr-interest] RFE: support for clean grammar

[Guntis Ozols]

For those [few?] of us who want grammar separated from implementation,
there should be some easy way to do that. It gives us (blah blah...):

- independence of target language
- independence of antlr version & antlr internals
- ability to use the same grammar file to generate
  parsers fitted for various purposes
  (highlighting, editing, interpreting, compiling, ...)
- simplified testing and debugging
- ...

(!) I believe it can be achieved in many cases with the following
very-easy-to-implement *command line* options:

  lexer.package
  parser.package
  lexer.superclass
  parser.superclass

To cover the rest, two things should be supported by *antlr grammar*
i.e. in target language independent way:

  no-arg method call (action)
  no-arg boolean function call (predicate)

That's it. This is one step away,
we can have (first in the world?) portable grammars in few hours

Please correct me if I am wrong or missing something

Thanks,
Guntis