Re: position of first matching regex

[AnomalousMonk]

Note also the general point that an expression like  $startloc = @- evaluates an array in scalar context and thus gives you the number of elements in the array, not the value of any particular element. See Context in perldata, and the tutorials Context tutorial, and Arrays: A Tutorial/Reference, in particular the section "Get count of elements".

[techtaskers.com]

Yup. That is an excellent goof on my part. I should be good at goofs, I've practiced all my life.

My two lessons here are that: (@- != $-[0]) && $-[0] requires /...(...).../ re positional variables.

Thank you for your reply.


David

[AnomalousMonk]

... $-[0] requires /...(...).../ re positional variables.

You show a capturing group in your example and refer to "positional variables", so I thought I'd mention that  $-[0] is the offset of the start of the overall match and does not depend at all on capture groups.

c:\@Work\Perl>perl -wMstrict -le
"my $s = 'xxxabcyyy';
 ;;
 print qq{overall match begining at offset $-[0] in '$s'}
   if $s =~ m{ abc }xms;
"
overall match begining at offset 3 in 'xxxabcyyy'

(And BTW: I've been practicing goofs for quite a while myself.)