One particular issue about regular expressions that bites me every once in a while is that the m//g modifier does not really find all matches, in the following sense:
$_ = "<Pooh,> said Rabbit kindly, <you haven't any brain> <I know,> s
+aid Pooh humbly.";
$ys = () = m/<[^>]*y/g; # count number of y's within angled brackets (
+assume no nesting)
prints "1", rather than "2". I understand why matching has to have this property, so instead I am looking for idioms
that people use in such situations. For example, if I wanted to do something else, replace all y's in angled brackets with x's, I would use 1 while s/(<[^>]*)y/$1x/g;
. However, this does not yield itself nicely to an analog for counting matches. Any ideas?
One thing that occured to me is perhaps using embedded code to count matches (i.e., if a match "almost succeeded", run some code that increments a counter and then make the match fail and retry elsewhere --- I don't know enough about embedding code to do this properly). Perhaps someone could provide some working code that would make this work?
Note: I would want "abcdef" =~ m/..*..*./g to return 20 = 6 choose 3 matches.