Re^4: pass code block to function (PROTOTYPES)

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
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UPDATE: of course, its an argument which is evaluated first!! thnx JavaFan

Comment on Re^4: pass code block to function (PROTOTYPES) Download Code

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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]