Hello fellow Monks,

I have a hash and need to look whether a combination of
its keys matches a searchstring. The thingie looks like that:

foreach my $combine (sort keys %$self) {
  if($key =~ /^$combine(.*)$/) {
    print "Found (prefix $combine): $1\n";
  }
  if($key =~ /^(.*)$combine$/) {
    print "Found (suffix $combine): $1\n";
  }
}

[download]
This works pretty well, but is pretty slow (big hash). Now
I see that much eficiency could be gained by using the sort
and just iterating through the sublist of keys containing the
same first char as the searchstring ($key).
Unfortunately I cannot figure out how to reduce the
sort keys %$self list without copying and
fiddling around. Also, I suspect that the regexp are way
too primitive and expensive for this simple task.

Has anyone a helping advice for me? Thank you very much.

Ciao

In reply to Fast sublist generation by PetaMem

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