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Re^2: Variable matching on a regex

by almut (Canon)
on Jun 17, 2010 at 14:47 UTC ( [id://845217]=note: print w/replies, xml ) Need Help??


in reply to Re: Variable matching on a regex
in thread Variable matching on a regex

not really sure why the last match doesn't get included or why the first one is undef

I think the capture group needs to be closed before being able to push its value.  This would work without further ado:

$data =~ /^(?:(\d+)\s*(?{ push @results, $^N }))+$/;


(Update)  P.S.: if you use this construct in a loop like in the OP's case, you need to declare the lexical @results outside of the loop for it to work properly.  I.e., while this is ok:

my @results; while (<DATA>) { @results = (); /^(?:(\d+)\s*(?{ push @results, $^N }))+$/; print "line $.: ", join('-', @results), "\n"; } __DATA__ 1 2 3 4 5 2 3 4 5 6 3 4 5 6 7

output:

line 1: 1-2-3-4-5 line 2: 2-3-4-5-6 line 3: 3-4-5-6-7

the following would work only once:

while (<DATA>) { my @results; /^(?:(\d+)\s*(?{ push @results, $^N }))+$/; print "line $.: ", join('-', @results), "\n"; }

output:

line 1: 1-2-3-4-5 line 2: line 3:


(Fixed /^(:?... typo — thanks eric256! )

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Re^3: Variable matching on a regex
by eric256 (Parson) on Jun 17, 2010 at 15:00 UTC

    Looks like minor typo at the start of the regex, but it works!

    $data =~ /(?:(\d+)\s*(?{push @results, $^N}))+$/;

    ___________
    Eric Hodges

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