Re: SIMILAR TO expressions translate wildcards where they shouldn't

On Fri, 2025-05-23 at 12:22 +0900, Michael Paquier wrote:
> Anyway, I don't think that the tests in the patch are complete. For
> example, '[[^](]' is transformed into '^(?:[[^](])$' in the SIMILAR TO
> conversion with the patch, and before the patch we get
> '^(?:[[^](?:])$'. Note the translation of the last parenthesis '(' to
> "(?:" when inside the character class, but your patch does not
> document that. AFAIU, we should not convert the parenthesis '(' while
> in a multi-level character class as the patch does, but we have no
> tests for it and the patch does not document this part, either.
>
> Could it be possible to split the single SIMILAR TO expression into
> multiple smaller pieces for each character that should not be
> converted while inside a character class? This is hard to parse as
> written in your proposal of patch.

I have changed the regression test like you suggest.

I also improved the code by adding more comments.
I renamed "incharclass" to "charclass_depth", which is more descriptive.

Also, I had to work some more on handling carets:
While the closing bracket is a regular character in []] and [^]], it
is not in expressions like [^^].

Yours,
Laurenz Albe