[antlr-interest] Re: (follow up) setting, altering text in lexer rules

Terence Parr parrt at cs.usfca.edu
Mon Jun 12 16:43:56 PDT 2006


On Jun 12, 2006, at 4:41 PM, Bill Canfield wrote:

>> Well the ! thing has always been a pain in the ass ;)  I'd rather opt
>> for speed for now with a workable solution and see what happens in
>> the future. :)
>
> Ter:
>
> One testcase I profiled (C++) used most of its time allocating more  
> and
> more space for the text of a multi-thousand-line comment that I was  
> just
> going to throw away anyway.  I was sure! glad! to! have! that
> exclamation point!!!
>
> I would like to second Don Caton's viewpoint:  pick good features and
> then optimize.

Hi Bill,

Yep.  I did to pick features to start with so that there IS no char  
copying by default, which is why the ! is such a huge pain this go  
around.  All tokens point into the char buffer, the correct  
approach.  It's very rare to modify more than a few tokens' text.  I  
believe I've made the right choice here.  For your comment case,  
you'll get love out of the box; no ! needed.  I call that a great  
invisible feature :)

Thanks to all for the comments!

Ter



More information about the antlr-interest mailing list