maria-developers team mailing list archive

[Oleksandr Byelkin <sanja@xxxxxxxxxxxxxxxx>]

Am 10.04.2018 um 10:58 schrieb Alexander Barkov:
>    Hello Sanja,
>
>
> I reviewed your recent changes in "10.3-MDEV-11953"
> (and the attached additional patch for sql_yacc_ora.yy)
>
> I have some proposals:
>
>
>
> 1. Can you please move huge pieces of the code from sql_yacc.yy to LEX
> or other relevant classes?
>
> It makes the grammar much more readable (patches are aslo much more
> readable).
>
> I'd move the relevant pieces of the code to LEX as a separate patch,
> even before fixing the grammar.
OK
> 2. You're adding too many main_select_push() and pop_select().
> Please move them to upper level rules (it should be possible in many cases).
Impossible
> Add new helper rules when needed.
> For example, this piece of code repeats many times:
>
> +          {
> +            if (Lex->main_select_push())
> +              MYSQL_YYABORT;
> +          }
> +          expr
> +          {
> +            Lex->pop_select(); //main select
> +            $$= $3;
>
> It deserved a rule, say, expr_with_select_push_pop.
> You can find a better name :)
OK
> - Serg and I spent a lot of time working on this task:
>    MDEV-8909 union parser cleanup
>    (and its 13 dependency tasks, and 3 related tasks,
>     see the "Issue links" section in MDEV).
>
> We think that it should be the parser who disallows bad grammar, instead
> of post-analysis with raising errors like
> ER_CANT_USE_OPTION_HERE.
> Please keep using the same approach.
The task did not made parser recognizing brackets, and I have no ideas 
how to return parser errors when all SELECT parsed in the same way in 
difference from the previous parser which could recognize only one level 
of SELECTs.
> Thanks!
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