Well, that's because $_[0]->seq() continues to return strings that have "CG" in them. And it probably returns a new string each time, or a copy of a string (which would be new), and then the match tries again.

What you probably want is: 

my $seq = $_[0]->seq();
while ($seq =~ /CG/) { ++$CG }

[download]
But I'm not sure about that. Are you trying to count the number of CG sequences? Then you want: 
$CG += () = $_[0]->seq() =~ /CG/g;

[download]
I think that "+=()=" may be called the "pimply-goatse-operator". Not sure. Ignore that.

What is it that this code is really trying to accomplish?

In reply to Re: Infinity loop by Tanktalus
in thread Infinity loop by doob

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