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Postings from May 2008
2008/5/5 Sébastien Aperghis-Tramoni <maddingue@free.fr>:
> While writing an article (in French) about 5.10 regexps, a reviewer found
> that what I wrote about \k<name> and $+{name} was inconsistent. I reread
> perlre and perlvar, and it seems that the inconsistency lies in perlvar:
>
> perlre/"Capture buffers" says:
>
> Outside the pattern, a
> named
> capture buffer is available via the "%+" hash. When different
> buffers
> within the same pattern have the same name, $+{name} and "\k<name>"
> refer to the leftmost defined group.
>
> and later in the "Extended Patterns" section:
>
> (?<NAME>pattern)
> [...]
> If multiple distinct capture buffers have the same name
> then
> the $+{NAME} will refer to the leftmost defined buffer in
> the
> match.
> [...]
>
> \k<NAME>
> Named backreference. Similar to numeric backreferences,
> except that the group is designated by name and not number.
> If multiple groups have the same name then it refers to the
> leftmost defined group in the current match.
>
> But perlvar says:
>
> %+ Similar to @+, the %+ hash allows access to the named
> capture buffers, should they exist, in the last successful
> match in the currently active dynamic scope.
>
>
> Now, if I understand correctly, perlre says that \k and %+ refers to the
> leftmost, IOW the *first* successful match, while perlvar says that %+
> refers to the *last* successful match.
> Or am I misunderstanding something?
I think you are. The last successful match is the last =~ test that
matched successfully; the currently active dynamic scope is the
current pair of {} braces. We're not inside a regexp there.
If you find a better wording I'll be glad to apply.
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