Class::Std::Utils(3pm) | User Contributed Perl Documentation | Class::Std::Utils(3pm) |
Class::Std::Utils - Utility subroutines for building "inside-out" objects
This document describes Class::Std::Utils version 0.0.3
use Class::Std::Utils; # Constructor for anonymous scalars... my $new_object = bless anon_scalar(), $class; # Convert an object reference into a unique ID number... my $ID_num = ident $new_object; # Extract class-specific arguments from a hash reference... my %args = extract_initializers_from($arg_ref);
This module provides three utility subroutines that simplify the creation of "inside-out" classes. See Chapters 15 and 16 of "Perl Best Practices" (O'Reilly, 2005) for details.
The typical usage is:
my %class_specific_args = extract_initializers_from($args_ref);
The argument hash is flattened as described in Chapter 16 of "Perl Best Practices":
In other words, given:
my $arg_ref = { key_1 => 'generic value 1', key_2 => 'generic value 2', 'Base::Class' => { key_1 => 'base value 1' }, 'Der::Class' => { key_1 => 'der value 1' key_2 => 'der value 2' }, }; package Base::Class; use Class::Std::Utils; my %base_args = extract_initializers_from($arg_ref); package Der::Class; use Class::Std::Utils; my %der_args = extract_initializers_from($arg_ref);
then %base_args would be initialized to:
( key_1 => 'base value 1', key_2 => 'generic value 2', 'Base::Class' => { key_1 => 'base value 1', }, 'Der::Class' => { key_1 => 'der value 1', key_2 => 'der value 2', }, )
whilst %der_args would be initialized to:
( key_1 => 'der value 1', key_2 => 'der value 2', 'Base::Class' => { key_1 => 'base value 1', }, 'Der::Class' => { key_1 => 'der value 1', key_2 => 'der value 2', }, )
That is, the top-level entries would be replaced by any second-level entries with the same key that appear in a top-level entry of the same name as the calling package.
This means that each class can just refer to $args{key_1} and $args{key_2} and be confident that the resulting values will be the most specific available for that class.
Class::Std::Utils requires no configuration files or environment variables.
Thsi module requires both the "Scalar::Util" and "List::Util" modules, which are standard in Perl 5.8 and available from the CPAN for earlier versions of Perl.
None reported.
The "Class::Std" module
"Perl Best Practices", O'Reilly, 2005.
No bugs have been reported.
Please report any bugs or feature requests to "bug-class-std-utils@rt.cpan.org", or through the web interface at <http://rt.cpan.org>.
Damian Conway "<DCONWAY@cpan.org>"
Copyright (c) 2005, Damian Conway "<DCONWAY@cpan.org>". All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
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2022-06-11 | perl v5.34.0 |