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Re^3: String Matching

by Jenda (Abbot)
on Aug 15, 2012 at 07:51 UTC ( #987517=note: print w/replies, xml ) Need Help??

in reply to Re^2: String Matching
in thread String Matching

They are greedy, but not too clever

my $str = "xaxaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"; $str =~ /(a+)/; print "$1\n"; # prints "a" not "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
The quantifiers are greedy, but they refuse to let go of something they found unless forced even if they could get more someplace later.

Enoch was right!
Enjoy the last years of Rome.

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Re^4: String Matching
by Anonymous Monk on Aug 15, 2012 at 07:54 UTC
    Um, they start from the left, stop when they find a match -- that is clever
      And predictable! I'd hate to regex in a world that wasn't predictable.
Re^4: String Matching
by AnomalousMonk (Chancellor) on Aug 15, 2012 at 16:33 UTC

    I'll see you and raise you.   /(a*)/ (note * quantifier in place of +) matches, but captures nothing, not even a single 'a'.

    >perl -wMstrict -le "my $s = 'xaxaaaaa'; print qq{matched, captured '$1'} if $s =~ /(a*)/; " matched, captured ''

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