in reply to Pseudo-switch question

This looks like good, idiomatic Perl code, fletcher -- nothing to worry about.

The one "side effect" is that it temporarily exposes the test value in the global $_, such that it could be accessed from within a subroutine called from within one of your # do something blocks, although this isn't likely to cause problems in properly written code.

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Re: Re: Pseudo-switch question
by pemungkah (Priest) on Jul 22, 2003 at 16:12 UTC
    And of course, if you use this in a sub you've clobbered $_. Add a 
    local $_;

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    previous to your preferred switch method and your callers will thank you.
[reply]
[d/l]
      Doesn't "for" always automatically localize "$_" like in this example? 
      my @list = qw(I Like tacos);

for (@list) {
  print "A:".$_."\n";
  for ("Hello") {
    print "B:".$_."\n";
  }
  print "C:".$_."\n";
}

      [download]
[reply]
[d/l]
      It is good that you considered that type of problem, but in this case, it is harmless.

      My rule of thumb is that when using a for/foreach loop, you do not need to localize $_, but if you are using a while(<>) loop, you must localize it.

      This is because the for/foreach loop is already doing the local step for you, but it is the only time that this happens.

[reply]
        You are indeed correct. I've just gotten into the habit of localizing globals when I'm about to alter them, and I want to be sure I didn't sabotage someone else up the line.

        I tend to assume that someone else reading the code might not think about $_ being global, alter the code so that $_ would get clobbered, and then be confused. If I've localized $_, and also commented why I've done it, it makes it easier to maintain. And I'm all about maintaining.

        I suppose the Right Thing would be to not localize and comment that the for loop does it for me. :)

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