Re^3: Missing $ on loop variable

Me and the ternary operator have a special relationship actually, i suppose it shows. Now that i take a more calm look at it, i'll take it one step further. I think the most elegant of all would actually be:

foreach (@keywords) {
    push @found, $_ if $line =~ m/$_/i;
}
[download]

next is not really useful, and dare i say obsolete, since there is no other code aside the regexp conditional in the foreach block. As for the grep rewrite, there is a gotcha, which might complicate things in certain situations. But i'll save it for another day since it isn't relevant to this thread. But if anyone is interested take a look here.

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Re^4: Missing $ on loop variable by revdiablo (Prior) on Dec 03, 2005 at 02:32 UTC
next is not really useful, and dare i say obsolete, since there is no other code aside the regexp conditional in the foreach block I'd say I agree it's not useful in this code, but calling it obsolete doesn't make a whole lot of sense. You must be operating with a different definition of obsolescence than I am. ;-) As for the grep rewrite, there is a gotcha, which might complicate things in certain situations. But i'll save it for another day Please, by all means, don't save it for another day. Even for those of us who might already know of this "gotcha", mentioning it without even narrowing it down is not all that nice (and no, linking to the grep docs does not narrow it down). :-)	[reply]
Re^5: Missing $ on loop variable by psychotic (Beadle) on Dec 03, 2005 at 14:39 UTC
As for the "obsolete" part, i used it --evidently badly-- as a synonym to "since there is no other code ... in the foreach block". Of course i was only refering to this snippet since `next` is invaluable in loop control. But i'm sure you knew that already. ;) As for the grep gotcha, here is the situation. Given this code: `my $line = "Alpha and some beta junk here"; my @keywords = qw(alpha beta gamma); foreach (grep { $line =~ /$_/i } @keywords) { $_ = rand; } foreach (@keywords) { print "$_\n" }` [download] We get when run: `0.623870849609375 0.16607666015625 gamma` [download] Grep aliases the current value of $_ to the original array element, and thus modifying it actually tampers our original data. It wasn't any special complication really, but has the potential to obfuscate a bug or two.	[reply] [d/l] [select]
Re^6: Missing $ on loop variable by revdiablo (Prior) on Dec 03, 2005 at 19:27 UTC
Grep aliases the current value of $_ to the original array element, and thus modifying it actually tampers our original data That's true, and good to point out. But it's also good to point out that `for` does the same thing. And the solution with grep is the same -- copy the values before modifying them. Which, incidentally, is exactly what my example snippet does. It copies the values into a new array. If you plug my example in just as I wrote it, the problem goes away: `my $line = "Alpha and some beta junk here"; my @keywords = qw(alpha beta gamma); my @found = grep { $line =~ /$_/i } @keywords; foreach (@found) { $_ = rand; } print "@keywords\n"; __OUTPUT__ alpha beta gamma` [download] So, while the gotcha didn't affect my example directly, I'm glad you brought it up. Anyone who wasn't aware of it will likely benefit from this discussion.	[reply] [d/l] [select]