On Jun 24, Richard Adams said:
> @peptides = $sequence =~ /(\w{4}S\w{4})/g;
>
>this works up to a point, but if there are 2 adjacent 'S' the 2nd one
>is not extracted, I guess because the regexp engine continues after the
>end of the previous match ie., it doesn't extract DFRSSSGHY above.
Here's the trick for you:
@peptides = $sequence =~ /(?=(\w{4}S\w{4}))/g;
The (?=...) assertion "looks ahead" in the string for the pattern, without
actually advancing in the string when it's done. In this way, we capture
something without advancing past it.
--
Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/
RPI Acacia brother #734 http://www.perlmonks.org/ http://www.cpan.org/
** Look for "Regular Expressions in Perl" published by Manning, in 2002 **
<stu> what does y/// stand for? <tenderpuss> why, yansliterate of course.
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