Re^2: pass code block to function (PROTOTYPES)

that makes a lot of sense!
I have now fix it as follows:

#! /usr/bin/perl

use strict ;
use warnings ;

    sub try (&@) {
        my($try,$catch) = @_;
        eval { &$try };
        if ($@) {
            $catch;
        }
    }
    sub catch (&) { &{$_[0]} }

    try {
        die "phooey";
    } catch {
        print "unphooey\n";
    };

catch { print "test\n"; } ;
[download]

thnx!

Comment on Re^2: pass code block to function (PROTOTYPES) Download Code

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Re^3: pass code block to function (PROTOTYPES) by JavaFan (Canon) on Jul 15, 2009 at 10:40 UTC
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.	[reply]
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]