[antlr-interest] Removing output=AST lets ANTLR fail to generate

[Christian]

Waoh, your interpretation of my words really shocked me ;)

I just asked if ANTLR could generate the lexer and parser without
AST-code if the option output=AST is removed. Apparently, it is not
possible so far. And please believe me, I was at no moment angry. But
back to the topic:

Feature request for ANTLR v4:
*Context:*
If you add AST shaping code to a given grammar and later change the
grammar itself, too, you cannot directly generate a pure lexer and
parser without AST shaping code anymore. You have to remove the AST
shaping code from the grammar to do it.
*Solution:*
If a combined grammar contains AST shaping code, it would be more
flexible if ANTLR is still able to generate non-AST target language code
when, e.g., the option output=AST is not defined.

I hope, my phrasing is better now ;)

Best regards,
Christian

Am 11.11.2011 16:33, schrieb Jim Idle:
> I think it might be the phrasing of your question. It may be a language
> barrier issue, but it sounds like "You stupid ANTLR asshats, why can't you
> do it this way, which is the way I expect it to work and so it must be the
> correct way; you are all stupid!"
>
> But...
>
> Clearly, as you get an error telling you that you have AST shaping code in
> there, then you cannot remove that option without removing the AST shaping
> directives. Whether or not that can be improved is not very relevant as
> 3.x is now in  maintenance mode while ANTLR 4 is being thrashed in to
> shape. So, perhaps you can rephrase your statement in to a feature request
> for ANTLR v4. It is a reasonable request if a little care is taken over
> the phrasing.
>
>
> Jim
>
>> -----Original Message-----
>> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
>> bounces at antlr.org] On Behalf Of Christian
>> Sent: Friday, November 11, 2011 12:15 AM
>> To: Eric; antlr-interest at antlr.org
>> Subject: Re: [antlr-interest] Removing output=AST lets ANTLR fail to
>> generate
>>
>>> As I understand it, you are creating a grammar and then remove
>>> output=AST
>> I created a combined grammar that contains operators and rewrite rules.
>> When I then remove the option "output=AST", the grammar is not
>> generated due to syntax errors. These syntax errors result from the
>> operators and rewrite rules. You can reproduce it with any
>> corresponding grammar you like.
>>
>> Christian
>>
>> Am 10.11.2011 18:33, schrieb Eric:
>>> I don't believe that anyone here is avoiding your question. I my self
>>> am unable to directly answer your question because it does not make
>>> sense to me. As I understand it, you are creating a grammar and then
>>> remove output=AST. Since you are expecting a lexer and parser as
>>> output, I must take it that you  are using a combined grammar. Based
>>> on the limited info given I see no reason why you are not getting an
>>> lexer and parser. If you were to post your grammar and the steps you
>>> take, someone here might spot something needing advise.
>>>
>>> Eric
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>     > Hi community,
>>>     >
>>>     > it seems that ANTLR cannot generate the lexer and parser if
>>>     output=AST
>>>     > is removed, but the operators and rewrite rules are still left
>>>     in the
>>>     > grammar. Am I right? If yes, that's really regrettable...and
>>>     unflexible.
>>>     > You could just ignore rewrite rules and operators, if output !=
>> AST,
>>>     > couldn't you?
>>>     >
>>>     > Regards,
>>>     > Christian
>>>
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