Class::...1Compat(3)

📦
version 2.25 · 12 versions
, in fedora 43

💖 NAME 💖

Okay bestie, welcome to the Class::...1Compat(3) page — brought to you by User Contributed Perl Documentation. The name is cursed, the Unix is real, and this is the V1 compatibility code for C::MM.

Class::MethodMaker::V1Compat — V1 compatibility code for C::MM.

🌸 SYNOPSIS 🌸

Bestie, listen: this class is for internal implementation only. It is not a public API. Like, do not come for it, it's not for public consumption.

✨ DESCRIPTION ✨

Class::MethodMaker version 2 is out here striving for backward-compatibility with version 1 as far as possible. That is to say, classes built with version 1 should work with few if any changes. Slay.

But the calling conventions for building new classes are significantly different: this is necessary to achieve a greater consistency of arguments. It's giving "we changed the vibe for your own good."

Version 2 takes all arguments within a single arrayref:

use Class::MethodMaker
  [ scalar => 'a' ];

If arguments are presented as a list, then Class::MethodMaker assumes that this is a version 1 call, and acts accordingly. Version 1 arguments are passed and internally rephrased to version 2 arguments, and passed off to the version 2 engine.

Thus, the majority of version 1 calls can be upgraded to version 2 merely by rephrasing. However, there are a number of behaviours that in version 1 that are internally inconsistent. These behaviours are mimicked in version 1 mode as far as possible, but are not reproducible in version 2 — to allow version 2 clients to rely on a more internally consistent interface. Periodt.

🧚 Version 2 Implementations 🧚

The nearest equivalent to each version 1 component (slot) available in version 2 is shown below using the indicated data-structures & options to create a component called a that mimics the V1 component behaviour as closely as possible:

abstract

use Class::MethodMaker
  [ abstract => 'a' ];

boolean

Boolean is available as a backwards compatibility hack, but there is currently no V2 equivalent. It is likely that some replacement mechanism will be introduced in the future, but that it will be incompatible with the version 1 boolean. Big "we'll circle back" energy.

code

use Class::MethodMaker
  [ scalar => 'a' ];

Let's face it, the v1 store-if-it's-a-coderef-else-retrieve semantics are rather broken. How do you pass a coderef as argument to one of these? It is on the TODO list to recognize code as fundamental restricted type (analogous to INTEGER), which would add in a *_invoke method.

copy

use Class::MethodMaker
  [ copy => 'a' ];

The v2 method is the same as v1.

counter

use Class::MethodMaker
  [ scalar => [{-type => Class::MethodMaker::Constants::INTEGER}, 'a'] ];

copy

deep_copy

The original page really does list copy again here, paired with deep_copy — I'm not arguing with the source, I'm just making it cute.

use Class::MethodMaker
  [ copy => [ -deep => 'a' ] ];

get_concat

use Class::MethodMaker
  [ scalar => [{ -store_cb => sub {
                                defined $_[1] ? ( defined $_[3] ?
                                                  "$_[3] $_[1]" : $_[1] )
                                              : undef;
                              }
               },
               'a' ]
  ];

get_set

use Class::MethodMaker
  [ scalar => 'a' ];

hash

use Class::MethodMaker
  [ hash => 'a' ];

key_attrib

Although v1 calls will continue to work, this is not supported in v2.

key_with_create

Although v1 calls will continue to work, this is not supported in v2.

list

use Class::MethodMaker
  [ list => 'a' ];

Note that the * method now sets the whole array if given arguments.

method

See code.

new

use Class::MethodMaker
  [ new => 'a' ];

new_hash_init

use Class::MethodMaker
  [ new => [ -hash => 'a' ] ];

new_hash_with_init

use Class::MethodMaker
  [ new => [ -hash => -init => 'a' ] ];

new_with_args

Although v1 calls will continue to work, this is not supported in v2, for it is a trivial application of new_with_init.

new_with_init

use Class::MethodMaker
  [ new => [ -init => 'a' ] ];

object

use Class::MethodMaker
  [ scalar => [{ -type    => 'MyClass',
                 -forward => [qw/ method1 method2 /] }, 'a' ]
  ];

object_tie_hash

use Class::MethodMaker
  [ hash => [{ -type      => 'MyClass',
               -forward   => [qw/ method1 method2 /],
               -tie_class => 'Tie::MyTie',
               -tie_args  => [qw/ foo bar baz /],
             }, 'a' ]
  ];

object_tie_list

use Class::MethodMaker
  [ array => [{ -type      => 'MyClass',
                -forward   => [qw/ method1 method2 /],
                -tie_class => 'Tie::MyTie',
                -tie_args  => [qw/ foo bar baz /],
              }, 'a' ]
  ];

set_once

use Class::MethodMaker
  [ scalar => [{ -store_cb => sub {
                                die "Already stored $_[3]"
                                  if @_ > 3;
                              }
               },
               'a' ]
  ];

set_once_static

use Class::MethodMaker
  [ scalar => [{ -store_cb => sub {
                                die "Already stored $_[3]"
                                  if @_ > 3;
                              },
                 -static   => 1,
               },
               'a' ]
  ];

singleton

use Class::MethodMaker
  [ new => [ -singleton => -hash => -init => 'a' ] ];

static_get_set

use Class::MethodMaker
  [ scalar => [ -static => 'a' ], ];

static_hash

use Class::MethodMaker
  [ hash => [ -static => 'a' ], ];

static_list

use Class::MethodMaker
  [ list => [ -static => 'a' ], ];

tie_hash

use Class::MethodMaker
  [ hash => [ { -tie_class => 'MyTie',
                -tie_args  => [qw/ foo bar baz /],
              } => 'a' ], ];

tie_list

use Class::MethodMaker
  [ array => [ { -tie_class => 'MyTie',
                 -tie_args  => [qw/ foo bar baz /],
               } => 'a' ], ];

tie_scalar

use Class::MethodMaker
  [ scalar => [ { -tie_class => 'MyTie',
                  -tie_args  => [qw/ foo bar baz /],
                } => 'a' ], ];

💀 Caveats & Expected Breakages 💀

The following version 1 component (slot) types are not currently supported in version 2. Not me being dramatic — that's just the situation:

  • grouped_fields
  • hash_of_lists
  • listed_attrib
  • struct

🦋 EXAMPLES 🦋

This section is empty in the original. No examples were provided — mysterious, lowkey iconic.

🐛 BUGS 🐛

Also empty in the original — no bugs listed here.

📮 REPORTING BUGS 📮

Email the development mailing list class-mmaker-devel@lists.sourceforge.net.

💜 AUTHOR 💜

Martyn J. Pearce.

Copyright (c) 2003, 2004 Martyn J. Pearce. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

👀 SEE ALSO 👀

No SEE ALSO references are listed in the original — the section is empty. No thoughts, head empty, but make it Unix.

💌 That's the whole page, bestie — this one shipped with perl v5.42.0, dated 2025-07-25, under the Class::...1Compat(3) manual. Periodt. 🫶

📦 where this page comes from