[tpm] problems with what regex returns ... in context ?

[Fulko Hew]

On Fri, May 10, 2013 at 1:33 PM, Quantum Mechanic <
quantum.mechanic.1964 at gmail.com> wrote:

> I would have tried "my" instead of the punctuation variables:
>
> if (my @capture = /$regex/) {
>     foreach @capture {
>         do something;
>     }
> }
>

That doesn't make any difference, @capture still (seems to get) the 1/true
result code
when there is no capturing.



> Cheers,
> QM
>
> On May 10, 2013, at 4:23 PM, Carlo Costantini <fifteen3 at gmail.com> wrote:
>
> > Because I was following along and thought others might be following as
> well. I thought I would summarize
> > what you discovered to help you with this situation.
> >
> > After looking up $+. I saw that there is also $& which has the string of
> the last pattern match.
> >
> > So to summarize:
> >
> > - a successful match with no captured data
> >
> > will have a $& value defined but will not have a $+ value defined.
> >
> > - a successful match with captured data
> >
> > will have both $& and $+ defined but you only need to check $+
> >
> > - an unsuccessful match
> >
> > $& will not be defined
> >
> >
> > Thank you for "thinking aloud", Fulko.
> >
> > --
> > Carlo
> >
> >
> > On Friday, 10 May, 2013 at 10:23 AM, Fulko Hew wrote:
> >
> >> Responding to my own post...
> >>
> >> I just discovered that I can test the defined-ness
> >> of $+ (the 'last' extraction) because I wasn't sure
> >> if $1 $2... would be _also_ defined, if I specified a list to return
> into.
> >>
> >> hmm, yes, $n are populated regardless of the left hand side
> >>
> >> Thanks
> >>
> >>
> >> On Fri, May 10, 2013 at 10:16 AM, Mike Stok <mike at stok.ca (mailto:
> mike at stok.ca)> wrote:
> >>> My perl is getting a little rusty, but the first thing I thought of
> was to check the defined-ness of $1 e.g.
> >>>
> >>> my $line = 'this is stuff in here';
> >>> my @patterns = qw / stuff (stuff) stuff/;
> >>> foreach $regex (@patterns) {
> >>> my @capture = ();
> >>> print "regex is '$regex' ... ";
> >>>
> >>> if ((@capture = ($line =~ m/$regex/)) && defined $1) {
> >>> print "captured " . scalar @capture . " items \n";
> >>> my $i = 0;
> >>> foreach my $item (@capture) {
> >>> print " capture[$i]: '$item'\n";
> >>> $i++;
> >>> }
> >>> } else {
> >>> print "nothing captured\n";
> >>> }
> >>> }
> >>>
> >>>
> >>>
> >>> I'm sure there's some problem with that though...
> >>>
> >>> Mike
> >>>
> >>> On 2013-05-10, at 10:06 AM, Fulko Hew <fulko.hew at gmail.com (mailto:
> fulko.hew at gmail.com)> wrote:
> >>>> my $line = 'this is stuff in here';
> >>>> my @patterns = qw / stuff (stuff) /;
> >>>> foreach $regex (@patterns) {
> >>>> my @capture = ();
> >>>> print "regex is '$regex' ... ";
> >>>> if (@capture = ($line =~ m/$regex/)) {
> >>>> print "captured " . scalar @capture . " items \n";
> >>>> my $i = 0;
> >>>> foreach my $item (@capture) {
> >>>> print " capture[$i]: '$item'\n";
> >>>> $i++;
> >>>> }
> >>>> } else {
> >>>> print "nothing captured\n";
> >>>> }
> >>>> }
> >>>
> >>> --
> >>>
> >>> Mike Stok <mike at stok.ca (mailto:mike at stok.ca)>
> >>> http://www.stok.ca/~mike/
> >>>
> >>> The "`Stok' disclaimers" apply.
> >>
> >> _______________________________________________
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> >> http://mail.pm.org/mailman/listinfo/toronto-pm
> >
> >
> >
> > _______________________________________________
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>
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