[antlr-interest] Q: move from v2 to v3 parser grammar. Rewrite tree rule

[Ruslan Zasukhin]

On 3/22/11 8:59 PM, "Jim Idle" <jimi at temporal-wave.com> wrote:

Hi Jim,

Thank you for answer.

> That is telling you that err, you can't use rewrite syntax AND an operator
> ;). Which one is it supposed to use?
> 
> So, remove any ^ and ! operators from the rule and use rewrite rules only.

Yes, this is clear now :)

> However, is that what you want to rewrite it as. I think you are using
> query_expression as that was what it looked like in v2. You might be
> better off abstracting in to two rules:
> 
> queryExpression
> : unionExpressions -> ^(QUERY_EXPRESSION unionExpressions) ;
> 
> unionExpressions
>      : query_term (( "union"^ | "except"^ ) "all"? query_term)* ;

So really 2 rules should be used as was in my first letter.
Okay, then we will make such changes in our grammar from v2

> However, using lower case literals in your parser directly is not a good
> idea.  Use real tokens so that you error messages are better

Simple example, please?


> and remember
> that SQL is generally case insensitive so you will need a [trivial] custom
> input stream.

Of course we do remember this :)

And after grammar start to breath, we will yet work on
* case-insensitive of SQL text
* UTF-16 for input  -- clarify ..



-- 
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]