[antlr-interest] ANTLR v2,v3
Anders Karlsson
anders at globe-trotter.us
Thu Aug 7 18:04:49 PDT 2008
> --------------------
> TO: Johannes Luber <jaluber at gmx.de>
> DATE: Thu, 07 Aug 2008 10:12:51 -0700
> SUBJECT: Re: [antlr-interest] ANTLR v2,v3
>
> On Thu, 2008-08-07 at 14:08 +0200, Johannes Luber wrote:
>
> Anders Karlsson schrieb: > Hi > > Is there a detailed list with grammar
> changes from v2 to v3. I have one big 140K v2 grammar to convert and I am
> really struggling so it would help with such a list. I have the book ANTLR3
> ref however there seems to be no helpful summary with the changes. e.g. in
> v2 you can write a:'t' to get an alias for 't' in v3 you have to write
> a='t' (if even true). Does <[LINK:
> http://www.antlr.org/wiki/pages/viewpage.action?pageId=719]
> http://www.antlr.org/wiki/pages/viewpage.action?pageId=719> help? > > I am
> not so familiar with the v2 grammar and was hoping not having to learn that
> dialect first when converting. > > Running the v2v3 just doesn't do it.
> The original grammar contains lots of sprinkled in C++ code and generates
> its own AST tree. > > I have also noticed that the ANTRLWorks1.1.7
> crashes when the grammar is big, it suddenly stops updating the screen. Is
> this a known problem? It happens when I do "Generate code". I noticed this
> behaviour myself, but Jean couldn't reproduce it, I believe. Send him a
> bug report with the grammar and generate the grammar on the command line.
>
> I think that this happens when the grammar is so far away from being a
> good one that the parsers are giving up all the time. Also, turn off the
> syntax autoupdate until the grammar is more like a v3 one.
>
> BTW - there are plenty of people that will convert your grammar for a
> fee, including me. If you are converting a C++ grammar, then all the
> actions (which should really be doing minimum work in actions and calling
> external code) will need to be changed. If you know neither the original
> C++ model in 2.7, nor the 3.1 C/C++ model, then you will be doing this
> conversion for a long time I suspect.
>
> Jim
Hi thanks for the update, I will try and turn off the auto-update. Unfortunately I cannot give out the grammar for troubleshooting due to company policy.
Thanks for your offer but I think this is something I myself need to do since it is part of my job. I don't currently have any firm requirement to convert to v3 but it will come next year so I was just investigating how much work it would be by some hands-on research.
Do you have any tips in how to approach the problem of converting a grammar, would be grateful for any pointers there. e.g. starting with this then doing that :)
Best regards
Anders
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