Attribute::Abstract - An Abstract attribute

Attribute-Util documentation Contained in the Attribute-Util distribution.

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NAME

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Attribute::Abstract - An Abstract attribute

SYNOPSIS

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  use Attribute::Abstract;

  package MyObj;
  sub new { ... }
  sub somesub: Abstract;

  package MyObj::Better;
  use base 'MyObj';
  sub somesub { return "I'm implemented!" }

DESCRIPTION

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This attribute declares a subroutine to be abstract using this attribute causes a call to it to die with a suitable exception. Subclasses are expected to implement the abstract method.

Using the attribute makes it visually distinctive that a method is abstract, as opposed to declaring it without any attribute or method body, or providing a method body that might make it look as though it was implemented after all.

BUGS

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None known so far. If you find any bugs or oddities, please do inform the author.

AUTHOR

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Marcel Grunauer, <marcel@codewerk.com>

Dan Kogai, <dankogai@dan.co.jp>

COPYRIGHT

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Copyright 2001 Marcel Grunauer. All rights reserved.

Copyright 2006 Dan Kogai. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

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perl(1), Attribute::Handlers

Attribute-Util documentation Contained in the Attribute-Util distribution. 
package Attribute::Abstract;

use warnings;
use strict;
use Attribute::Handlers;

our $VERSION = sprintf "%d.%02d", q$Revision: 1.1 $ =~ /(\d+)/g;

sub UNIVERSAL::Abstract :ATTR(CODE) {
	my ($pkg, $symbol) = @_;
	no strict 'refs';
	my $sub = $pkg . '::' . *{$symbol}{NAME};
	*{$sub} = sub {
		my ($file, $line) = (caller)[1,2];
		die "call to abstract method $sub at $file line $line.\n";
	};
}

"Rosebud"; # for MARCEL's sake, not 1 -- dankogai

__END__