Scalar::Util::Instance - Generates and installs is-a predicates

This document describes Scalar::Util::Instance version 0.001.

    use Scalar::Util::Instance
        { for => 'Foo', as => 'is_a_Foo' },
        { for => 'Bar', as => 'is_a_Bar' },
    ;

    # ...
    if(is_a_Foo($_)){
        # ...
    }
    elsif(is_a_Bar($_)){
        # ...
    }

Scalar::Util::Instance provides is-a predicates to look up an is-a hierarchy for specific classes. This is an alternative to blessed($obj) && $obj->isa(...), but is significantly faster than it.

Generates an is-a predicate function for ClassName.

If PredicateName is specified, the method installs the generated function as that name. Otherwise returns an anonymous CODE reference.

An is-a predicate is a function which is the same as the following:

    sub is_a_some_class {
        my($obj) = @_;
        return Scalar::Util::blessed($obj) && $obj->isa($ClassName);
    }

Perl 5.8.1 or later, and a C compiler.

No bugs have been reported.

Please report any bugs or feature requests to the author.

Scalar::Util

Data::Util

Goro Fuji (gfx) <gfuji(at)cpan.org>

Copyright (c) 2009, Goro Fuji (gfx). Some rights reserved.

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