MooseX::Types::VariantUsereContributed)MooseX::Types::VariantTable::Declare(3)NAMEMooseX::Types::VariantTable::Declare - Declarative sugar for
MooseX::Types::VariantTable based methods.
SYNOPSIS
package Awesome;
use Moose;
variant_method dance => Item => sub {
# Item is the least derived type in the hierarchy,
# every other type subtypes it
# this is in effect a fallback
return "fallback";
};
# a more specific type
variant_method dance => Ballerina => sub {
my ( $self, $ballerina, @args ) = @_;
$ballerina; # a value that passed the TC named "Ballerina"
return "pretty!";
};
# also works with objects
variant_method dance => $type_object => sub { ... };
DESCRIPTION
This module provides declarative sugar for defining
Moose::Meta::Method::VariantTable methods in your Moose classes and
roles.
These methods have some semantics:
Declaration
The order of the declarations do not matter in most cases.
It is the type hierarchy that defines the order in which the
constraints are checked and items dispatched.
However, in the case that two constraints without an explicit
relationship between them (one is a subtype of the other) both accept
the same value, the one that was declared earlier will win. There is no
way around this issue, so be careful what types you use especially when
mixing variants form many different sources.
Adding the same type to a variant table twice is an error.
Inheritence
When dispatching all of the subclass's variants will be tried before
the superclass.
This allows shadowing of types from the superclass even using broader
types.
Roles
... are currently broken.
Don't use variant table methods in a role, unless that's the only
definition, because in the future variant table merging will happen at
role composition time in a role composition like way, so your code will
not continue to work the same.
POD ERRORS
Hey! The above document had some coding errors, which are explained
below:
Around line 121:
=back without =over
perl v5.14.12010-MooseX::Types::VariantTable::Declare(3)
