Suppose you set up the following: 

use Data::Dumper qw(Dumper);

$SIG{__WARN__} = sub { &handle_it(@_); warn @_ };
$SIG{__DIE__}  = sub { &handle_it(@_);  die @_ };

sub handle_it {
  print Dumper \@_;
}

[download]


Everything looks great. Should be able to spit out arguments that were passed. Except the following happens: 

die "foo";    # prints as "foo at script line whatever\n" - stringifie
+d
#die "foo", "foo";  # stringified - same as above but with "foofoo"
#die {hi => 'there'};  # not stringified - shows correctly as a hashre
+f
#die 'foo',{hi => 'there'}; # stringified "fooHASH{whatever}"
#warn {hi => 'there'};  # always stringified

[download]


So, rather than being able to have useful handlers, we are left with a mess. Granted the one case that didn't stringify is great for Object Exceptions like die My::Exception->whatever('foo'), the reason for stringifying in the other cases is mind boggling. It seems that perl should leave the arguments alone until somebody calls die from inside a $SIG{__DIE__} handler or warn from inside the $SIG{__WARN__} handler. I'm sure its all an "internals" issue but still it seems like a poor choice to almost, but not quite, provide the data that was passed along.

So my question. Is there a way turn off stringification entirely for this case. I know that I could send an object as a parameter with a better overloaded stringification mechanism - but that is overkill. I'd love to be able to do: 

die "Something happend", {extra_argument_to_show_pretty_error => 1};

[download]


I haved looked but my guess is I get to wait for Perl 6 Exceptions.

Thanks for any help.

my @a=qw(random brilliant braindead); print $a[rand(@a)];

In reply to Argument stringification in __WARN__ and __DIE__ by Rhandom

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