I'm trying to understand how multiple quantifiers in a
regular expressions get massaged to fit the data.
in other words.
my $string = "was not was not was not the time was not was not was not was not
";
if($string =~ m{(.*)was(.*)the time}) {
print "matched\n";
print "1 is '$1'\n";
print "2 is '$2'\n";
}
The first (.*) swallows the whole string,
and fails when it sees "was" in the regular
expression, so it backs up until it can find
a "was" in the string, and then it fails when
it looks for "the time", so it backs up again
until it finds a "was" followed by "the time".
I know it "just works", but I'm trying to figure
out exactly how it behaves under the hood.
I think if I were to write it in pseudocode,
it would look something like this:
foreach my $quantifier ( @list_of_quantifiers ) { # ($1 .. $n)
while(nomatch) {
$quantifier->reducecaptureby1andtryagain;
}
But I think there might be other ways of
implementing it that would be subtly diffferent.
anyone?
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