use Perl

• do FIRST not BEFORE (Score:1)

  by salva (841)

  Executing FIRST before anything in the loop makes it pretty uninteresting. It would be more useful if it were run conditionally but on its place.

  About implementing it, how about maintaining a loop iteration counter in some internal variable as $?I.

  The same applies for LAST, but how do you know you are running the last iteration until after the loop check has failed?
  • Re: (Score:1)

    by masak (6289)

    Executing FIRST before anything in the loop makes it pretty uninteresting. It would be more useful if it were run conditionally but on its place.

    ...and that, to be clear, is how it's spec'd to work, and how I actually end up implementing it in the post.

    The same applies for LAST, but how do you know you are running the last iteration until after the loop check has failed?

    Also addressed in the blog post in whose comment thread you are commenting. :)
    • Re: (Score:1)

      by salva (841)

      It seems I have not explained my opinion clearly, let me illustrate it with some code:

      for 1..3 { say "enter"; FIRST { say "first run" } LAST { say "last run" } say "leave" }

      I would consider FIRST and LAST to be interesting if that code printed enter, first run, leave, enter, leave, enter, last run, leave.
      • Re:do FIRST not BEFORE (Score:1)

        by Aristotle (5147) <pagaltzis@gmx.de> on 2010.07.18 15:47 (#72176) Homepage Journal

        for 1..3 {
            my $first; FIRST { $first = 1 }
            my  $last;  LAST {  $last = 1 }
        
            say "enter";
            if $first { say "first run" }
            if $last  { say "last run" }
            say "leave"
        }

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        • Re: (Score:1)

          by Aristotle (5147)

          Oops. That won’t work for LAST, though it does for FIRST. Hmm.