[antlr-interest] stuff I don't like about ANTLR 2.x

[Ric Klaren]

On Sat, Mar 06, 2004 at 12:05:24PM -0800, Terence Parr wrote:
> Feel free to send in your pet peeves to me or to this list.  I will try
> to add to this file.

Part 2:

- Clear semantics for things like:

  ( { x < 4 }? myRule )*
  ( { x < 4 }? myRule )+

- Clear documented semantics for the scope of a variable defined in actions:

    (  { int somevar; }

    )*

  Or:

    (  { int somevar; } :

    )*

  Or dirty stuff like:

    (  { if( i > 10 ) break;  } :
      someRule
    )*

    (  { if( i > 10 ) throw ....;  } :
      someRule
    )*

  Or a statement like 'You're on your own!'.

- Consistent importVocab/exportVocab behaviour when the lexer/parser are in
  the same file and in the separate files cases.

- it would be nice if ANTLR would examine dependent grammars and remake them
  if needed. Would probably require some extra options for specifying the
  search path for grammars/vocabs. (we definitely need more control for
  this as someone else pointed out as well)

- It would be nice if ANTLR3 was designed from the outset for heterogeneous
  AST and Token support. In antlr2 this was not the case and it shows.

- I would love a shorthand syntax for:

  ( stuff ) ( DELIMITER stuff )*

  Where delimiter is usual a single token or a set of tokens. The advantage
  is that the action code for stuff can be the same. In the current
  implementation you have to keep some near identical bits of code
  synchronized with the occasional copy paste error resulting from that.

  ell used a syntax like ( stuff || DELIMITER )* or something along those
  lines.

- It would be nice if antlr would warn for common mistakes like 
  rule* in stead of ( rule )*
  
Cheers,

Ric
--
-----+++++*****************************************************+++++++++-------
    ---- Ric Klaren ----- j.klaren at utwente.nl ----- +31 53 4893722  ----
-----+++++*****************************************************+++++++++-------
  "I think we better split up."
  "Good idea. We can do more damage that way."
  --- Ghostbusters



 
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