Re^2: the try/catch example from "Programming Perl" analyzed

Not sure that the nested if is actually needed. This code works with string and object exceptions (on 5.8.3 at least):

use strict;
use warnings;

package Exception;

package IOException;
@IOException::ISA = qw(Exception);

package OtherException;
package YetAnotherException;

package main;

*isa = \&UNIVERSAL::isa;

my @grisly = (
    sub { die "AARRGH!\n" },
    sub { die bless [], 'Exception' },
    sub { die bless [], 'IOException' },
    sub { die bless [], 'OtherException' },
    sub { die bless [], 'YetAnotherException' },
    sub { print "I live\n"; }
);

sub do_something_that_could_die
{
    $grisly[0]->(); # or int(rand(@grisly))
}

eval {
    do_something_that_could_die();
};
if(isa($@, 'Exception')) {
    print  ref($@), ' caught';
}
elsif(isa($@, 'OtherException')) {
    print  ref($@), ' caught';
}
elsif(ref $@) {
    # handle any other exception object
    print  ref($@), ' caught';
}
elsif($@) {
    # handle non-object exception
    print $@;
}
[download]

Update:
replaced $@->isa('package') calls with calls to UNIVERSAL::isa()

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Re^3: the try/catch example from "Programming Perl" analyzed by gellyfish (Monsignor) on Aug 19, 2004 at 14:43 UTC
As long as you are sure you are going to get an object. You may want to use the functional UNIVERSAL::isa() if you want to avoid your 'catch' crapping out when something does just a plain `die $!` /J\	[reply] [d/l]
Re^4: the try/catch example from "Programming Perl" analyzed by Arunbear (Prior) on Aug 19, 2004 at 14:55 UTC
Thanks, it would also have crapped out if $@ was undefined.	[reply]


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