Class::MethodMaker::V1Compat(3pm)
NAME
Class::MethodMaker::V1Compat - V1 compatibility code for C::MM
SYNOPSIS
This class is for internal implementation only. It is not a public API.
DESCRIPTION
Class::MethodMaker version 2 strives for backward-compatiblity with
version 1 as far as possible. That is to say, classes built with
version 1 should work with few if any changes. However, the calling
conventions for building new classes are significantly different: this
is necessary to achieve a greater consistency of arguments.
- 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). - Version 2 Implementations
- The nearest equivalent to each 1 component (slot) available in version
2 is shown below using the indicated data-structures & options to
create a component called "a" that mimicks the V1 component behaviour
as closely as possible: - abstract
use Class::MethodMaker[ abstract => 'a' ];
- boolean
- Boolean is available as a backwards compatiblity 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. - 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 - 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: - grouped_fields
hash_of_lists
listed_attrib
struct
EXAMPLES
BUGS
REPORTING BUGS
Email the development mailing list
"class-mmaker-devel@lists.sourceforge.net".
AUTHOR
Martyn J. Pearce
COPYRIGHT
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.