Re^4: How does 'goto LABEL' search for its label? (yow?)

> Now, I think using goto to leave a subroutine is a rather squirrely technique.

It's a way to directly break out of a deep recursion.

my $counter;

sub rec {
  goto OUT if $counter++ >= 10;
  print $counter;
  rec();
  # never reached
}

rec();
OUT:
[download]

This can be handy to avoid the code-block after a recursive call w/o needing to check a status-flag.

Cheers Rolf

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Re^5: How does 'goto LABEL' search for its label? (yow!) by tye (Sage) on Jan 17, 2013 at 04:07 UTC
I didn't say it should be disallowed. I said it is squirrely. In particular, it is easy to see doing this by accident. So it is appropriate to issue a warning which even provides the opportunity to add a line indicating "yes, I really did intentionally use 'goto' to exit this subroutine". And die is a less squirrely way to unwind a stack. - tye	[reply]
Re^6: How does 'goto LABEL' search for its label? (yow!) by LanX (Saint) on Jan 17, 2013 at 04:11 UTC
> I didn't say it should be disallowed. I didn't say you did! :) Just wanted to show a motivation for this technique. > And die is a less squirrely way to unwind a stack. ehm ... you mean within an `eval` block? Well tastes differ... EDIT: Hmm ... at least `die` can easily send a message... Cheers Rolf	[reply] [d/l] [select]