It is a trade off, as you guess. The features that come with v3 demanded some changes and sometimes you have to lose a few conveniences. The lexer/token changes were driven by performance for instance, whereby copying text in to the token whether you were going to use it or not was a performance hit.
You will probably see a few other things that may 'annoy' you at first, but they are changes for good reason :) Jim > -----Original Message----- > From: [email protected] [mailto:antlr-interest- > [email protected]] On Behalf Of Ruslan Zasukhin > Sent: Wednesday, March 23, 2011 5:41 AM > To: [email protected] > Subject: Re: [antlr-interest] Q: move from v2 to v3 parser grammar. > Rewrite tree rule > > On 3/23/11 1:54 AM, "Jim Idle" <[email protected]> wrote: > > Hi Jim, > > > You can do it the same way in v3, but when you generate the code, > > ANTLR will make up token names and you won't be able to write a good > > error display routine/handler because you won't know the tokens. You > > will just have T23 or something like that, and then you can't do > > anything interesting. So, you don't HAVE to, but it is neater when > you > > come to do certain things. > > Aha, I see. > Yes we have see that T23 a lots in generated code .. > > > Interesting ... In v2 names of tokens was shown correctly Right? > > > In v3 probably was some changes in architecture, Which prevent from > this nice automatic feature .. > > > Hmm. Actually it is not good, when a newer version loose nice features. > :-) > > Again, thank you very much Jim for points. > > > > ========== > Before click SEND button have come strange [and OPTIONAL] question to > mind. > > If v3 was designed to support old AST operators ^ ! > And new re-write rules (ok for new) > > But why was trashed feature of ## = (IMAGE_TOKEN, ##) ? > picture is broken. > two operators self cannot resolve all tasks .. > > > If it was not touched, then porting was much easier I think. > > Or I do not see big idea behind of this step? > > > -- > Best regards, > > Ruslan Zasukhin > VP Engineering and New Technology > Paradigma Software, Inc > > Valentina - Joining Worlds of Information http://www.paradigmasoft.com > > [I feel the need: the need for speed] > > > > List: http://www.antlr.org/mailman/listinfo/antlr-interest > Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your- > email-address List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups "il-antlr-interest" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
