May I infer from the fact that typeglobs are going away that
we will no longer be able to use in our code such lovely global
variables as @31415, %42, the filehandle */, etc? I assume that
the availability of such was merely an unintended side-effect of the
special like-named scalars and the conf
This and other RFCs are available on the web at
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=head1 TITLE
Regular Expression Special Variables
=head1 VERSION
Maintainer: Uri Guttman <[EMAIL PROTECTED]>
Date: 25 Aug 2000
Last Modified: 22 Sep 2000
Mailing List: [EMAIL PROTECTED]
Number: 158
V
This and other RFCs are available on the web at
http://dev.perl.org/rfc/
=head1 TITLE
Regular Expression Special Variables
=head1 VERSION
Maintainer: Uri Guttman <[EMAIL PROTECTED]>
Date: 25 Aug 2000
Last Modified: 22 Sep 2000
Mailing List: [EMAIL PROTECTED]
Number: 158
V
p pairs are populated with offsets
into the target string
- immediately after matching, the target string is copied if needed,
and the PL_curpm object is updated to refer to the copy
- the copy is needed if any of the special variables can be referred
to: $`, $&, $', $1, $2, .
> But maybe the effect of $& is greatly exaggerated or is a relic from
> perl4? Has anyone actually benchmarked this recently?
Matching with $& enabled is about 40% slower.
http://www.plover.com/~mjd/perl/amper.pl
> >Please correct me if I'm mistaken, but I believe that that's the way
> >they are implemented now. A regex match populates the ->startp and
> >->endp parts of the regex structure, and the elements of these items
> >are byte offsets into the original string.
>
> I haven't looked at it at all
Tom Christiansen wrote:
> There's also long been talk/thought about making $& and $1
> and friends magic aliases into the original string, which would
> save that cost.
I was distressed to discover that s///g does not rebuild the
old string between matches, but only at the end. It broke my
ran
> "MD" == Mark-Jason Dominus <[EMAIL PROTECTED]> writes:
>> There's also long been talk/thought about making $& and $1
>> and friends magic aliases into the original string, which would
>> save that cost.
MD> Please correct me if I'm mistaken, but I believe that that's the way
MD>
>> There's also long been talk/thought about making $& and $1
>> and friends magic aliases into the original string, which would
>> save that cost.
>Please correct me if I'm mistaken, but I believe that that's the way
>they are implemented now. A regex match populates the ->startp and
>->endp p
> There's also long been talk/thought about making $& and $1
> and friends magic aliases into the original string, which would
> save that cost.
Please correct me if I'm mistaken, but I believe that that's the way
they are implemented now. A regex match populates the ->startp and
->endp parts
> "TC" == Tom Christiansen <[EMAIL PROTECTED]> writes:
TC> Those weren't the scripts I was thinking about, and it is *NOT*
TC> ipso facto true that something which uses $& or $` is poorly
TC> written.
i wasn't claiming that. a short script using $& would be fine where you
don't care ab
>those early perl3 scripts by lwall floating around in /etc were poorly
>written. i am glad they are finally out of the distribution.
Those weren't the scripts I was thinking about, and it is *NOT*
ipso facto true that something which uses $& or $` is poorly
written.
--tom
> "TC" == Tom Christiansen <[EMAIL PROTECTED]> writes:
>> $`, $& and $' are useful variables which are never used by any
>> experienced Perl hacker since they have well known problems with
>> efficiency.
TC> That's hardly true. I could show you plenty of code from
TC> inexperienc
>$`, $& and $' are useful variables which are never used by any
>experienced Perl hacker since they have well known problems with
>efficiency.
That's hardly true. I could show you plenty of code from
inexperienced Perl hackers like lwall that use them. But
the cost in understood. :-)
The res
>First, $`, $& and $' will be scoped just like $1 and friends. They will
>be set by the regex and be only accessible in the current block or a
>block which starts with a regex like:
>
> if ( /foo/ ) {
Good idea. $`, $&, and $' will be used immediately 99% of the time.
For the rest of the
This and other RFCs are available on the web at
http://dev.perl.org/rfc/
=head1 TITLE
Regular Expression Special Variables
=head1 VERSION
Maintainer: Uri Guttman <[EMAIL PROTECTED]>
Date: 25 Aug 2000
Version: 1
Mailing List: [EMAIL PROTECTED]
Number: 158
=head1 AB
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