in reply to What's the point of a labeled block without a loop?

I use it sometimes for processing STDIN (the few times I ever need to). redo is your friend. 
my $age;
INPUT: {
    print "Please enter your age: ";
    $age = <STDIN>;
    if ( $age !~ /\D/ ) {
        last INPUT;
    }
    redo INPUT;
}

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My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

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Re^2: What's the point of a labeled block without a loop?
by BrowserUk (Patriarch) on Dec 17, 2005 at 00:10 UTC

    Is there any specific advantage to the label there?

    That appears to work just as well with none (except you need a chomp).

    I'm not much taken with "if $age does not contain a non-digit, were done". How about: 

    my $age;
{
    print "Please enter your age: ";
    chomp( $age = <STDIN> );
    redo if $age =~ /\D/;
}

Please enter your age:
Mind your own
Please enter your age:
As old as m'tongue and a little older than m'teeth.
Please enter your age:
300000000000

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    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
      The only real benefit is reader clarity. By labelling it, you're giving a reason for a bare-block.

      Also, my personal style - I (mostly) always put a label with every last and redo. (I don't for next because next is much more common.)

      My criteria for good software:
      1. Does it work?
      2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?
[reply]
        By labelling it, you're giving a reason for a bare-block.

        In this specific case, it can be done without a bare block:

        my $age;
do {
    print "Please enter your age: ";
    chomp ($age = <STDIN>);
} while $age =~ /\D/;
print "Got it: $age\n";
__END__  
Please enter your age: hi there
Please enter your age: 123abc
Please enter your age: 99
Got it: 99

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        --
        David Serrano

[reply]
[d/l]
        By labelling it, you're giving a reason for a bare-block.
        Huh? Do you really mean to say that the label is the reason for the bare block?
        Perl --((8:>*
[reply]

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