Re^3: pass code block to function (PROTOTYPES)

That doesn't make any sense. Now the argument of catch will be executed even before try is called. You've broken the entire reason of having a try/catch system.

Why do you want to call catch directly anyway? It's like calling else without an if, or a continue without a while.

Comment on Re^3: pass code block to function (PROTOTYPES)

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Re^4: pass code block to function (PROTOTYPES) by jeanluca (Deacon) on Jul 15, 2009 at 12:05 UTC
think of catch as some function. I don't really care about the try/catch, I've used the code as a starting point for my experiments! UPDATE: But why is catch executed before try ? `#! /usr/bin/perl -l use strict ; use warnings ; sub try (&@) { my($try,$catch) = @_; eval { &$try }; if ($@) { $catch; } } sub catch (&) { &{$_[0]} } try { die "phooey"; } catch { /phooey/ and print "unphooey\n"; }; __END__ output: Use of uninitialized value in pattern match (m//) at ./tc.pl line 18` [download] UPDATE: of course, its an argument which is evaluated first!! thnx JavaFan	[reply] [d/l]
Re^5: pass code block to function (PROTOTYPES) by JavaFan (Canon) on Jul 15, 2009 at 13:04 UTC
But why is catch executed before try ? Because perl5 doesn't have lazy evaluation. If you call a function, perl will evaluate all its arguments. And since `catch {/phooey/ and print "unphooey\n"}` is one of the arguments of `try`, `catch` is called first. Which is why it's important that `catch` just returns its first argument, not evaluates it. And that's why you're getting the warning.	[reply] [d/l] [select]