Class::MethodMaker::V1UseraContributed Perl DocClass::MethodMaker::V1Compat(3)NAMEClass::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
EXAMPLESBUGSREPORTING 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.
SEE ALSOperl v5.18.1 2011-02-28 Class::MethodMaker::V1Compat(3)
