[Python-ideas] Ignorable whitespaces in the re.VERBOSE mode

[Serhiy Storchaka]

21.11.17 04:20, Stephen J. Turnbull пише:
> Serhiy Storchaka writes:
>   > I agree. But if there is a special part of the Unicode standard for
>   > Pattern White Spaces which includes non-ASCII characters, perhaps there
>   > is a need in them. I asked for the case if Python developers with very
>   > different cultures have need in additional whitespaces in regular
>   > expressions, but I don't know. Seems nobody has claimed their need.
> 
> I doubt that Japanese would want it.  I do use \N{IDEOGRAPHIC SPACE} a
> bit as a *target* of regular expressions, but I would never want it as
> non-syntactic in re.VERBOSE.  (Of course, I'm not a native Japanese, but
> I have never heard a Japanese developer wish for use of that character
> in any programming language, outside of literal strings.)
> 
>   > In particularly I don't know how helpful would be supporting
>   > right-to-left and left-to-right marks in verbose regular expressions
> 
> That's a good question.  Interpretation and display of R2L in
> programming constructs came up briefly in the discussions about BIDI
> on the emacs-devel list.  I'll ask Eli Zaretskii, who implemented it
> for Emacs.

Thank you Stephen. I would prefer to not change anything (because 
supporting additional whitespaces will complicate and slow down the 
code, and can add subtle bugs, add likely will add a confusion for 
users). But I want to know whether there is a real need in supporting 
additional whitespaces and rtl and ltr marks in regular expressions and 
Python syntax.