[antlr-interest] antlr v4 wish list

[Gary Miller]

Terence,

As I have mentioned I'm newish to Antlr.
I think that means that only now I'm starting to do things the "proper" way.

Here are a couple of items that I would have on a wish list.
Please let me know which of them are simply from a newbee perspective
and just ignore the one that are already on the wish list.

- Access to override rules, particularly in tree grammars.
  As discussed in
http://www.antlr.org/pipermail/antlr-interest/2011-March/041052.html

- The ability to have actions on the right side of an ast re-write operator.
  I remember this confusing me as the same syntax is used for actions
and Creating Nodes with Arbitrary Actions, but they have different
sematics
  An example of using this would allow for collecting symbols during
parsing or action during tree walking with AST output or rewriting.

- A different rule @init that only executes during when not backtracking.

- The ability to detect / work with an empty scope.
  Currently attempts to access an empty scope throws a stack exception (in Java)

- Lexing (this is still the most confusing aspect of parsing for me)
  - Case insensitive lexing.
    I know this is possible, and I currently do with info from
http://www.antlr.org/wiki/pages/viewpage.action?pageId=1782

  - Block lexing options, ala Jyhton's PythonTokenSource and lexer in Python.g

  - The ability to dynamically change the channel tokens go to
      or
    The ability tack hidden token to the end of the last visible token.


Regards
Gary


On Wed, Mar 23, 2011 at 8:21 AM, Gary Miller <gary at sumwise.com> wrote:
> Terence,
>
> The ANTLR4 Wiki isn't publicly accessible.
>
> Regards
> Gary
>
>> Date: Tue, 22 Mar 2011 10:45:48 -0700
>> From: Terence Parr <parrt at cs.usfca.edu>
>> Subject: [antlr-interest] antlr v4 wish list
>> To: antlr-interest Interest <antlr-interest at antlr.org>
>> Message-ID: <F8A011FA-9DBE-4024-8982-2D9EC66849E9 at cs.usfca.edu>
>> Content-Type: text/plain; charset=us-ascii
>>
>> Howdy, I'm going to start augmenting ANTLR v3 significantly to create v4. The goal is backward compatibility; any new functionality, of course, will require altering or augmenting your grammars to take advantage of it. Here is my potential list of updates:
>>
>> http://www.antlr.org/wiki/display/ANTLR4/ANTLR+v4+Wish+list
>>
>> Anything to add or comment on?
>>
>> Ter
>