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Postings from October 2015
On 19 October 2015 at 04:50, Ricardo Signes <perl.p5p@rjbs.manxome.org> wrote:
> * Karl Williamson <public@khwilliamson.com> [2015-10-18T00:16:44]
>> Just to make sure everyone understands.
>>
>> Currently (?#...) comments are allowed even when there is no /x. We
>> probably have to support that in the places where it's been that way all
>> along, but we could decide to not support them in the places that I just
>> added, when not under /x. Thus, we could say that you can't split a
>> quantifier from its atom except under /x.
>
> Thanks, I was confused.
>
>> I don't have an opinion on this.
>
> I'm not strongly opinionated on this, but: I think that I would find it useful
> to say:
>
> If you want to put comments into a regular expression, you have two
> options. You use /x and then insert space and any kind of comments between
> tokens, or you can skip /x and use (?#...) between tokens.
>
> That is: always allow (?#...) in those places where space and comments become
> allowed under /x.
I really dont like this. A) it complicates the regex engine, and B) it
makes a mockery of what an expert would consider to be one token.
so for instance to *me*: a{1,10} is a single token.
a(?#whatever){1,10}
is two "tokens".
I think expecting people to grok that
/a
{1,10}/x
is the same as /a{1,10}/x
is IMO just asking for trouble and for people to misunderstand what is going on.
Related, would you expect
\(?#is this a \w match or not)w
to be the same as
\w
?
Its not, but IMO if you think that a(?#foo){1,10} should be the same
as a{1,10} then why shouldnt \(?#whatever)w?
Of course, it wouldnt work, as \( would mean that (?#whatever) is not
treated as a comment at all.
So this idea just increases inconsistency in our regexes for IMO
basically no value.
Yves
--
perl -Mre=debug -e "/just|another|perl|hacker/"
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