1Moose::Meta::TypeConstrUasienrt(C3o)ntributed Perl DocumMeonotsaet:i:oMneta::TypeConstraint(3)
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NAME

6       Moose::Meta::TypeConstraint - The Moose Type Constraint metaclass
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VERSION

9       version 2.2014
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DESCRIPTION

12       This class represents a single type constraint. Moose's built-in type
13       constraints, as well as constraints you define, are all stored in a
14       Moose::Meta::TypeConstraint::Registry object as objects of this class.
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INHERITANCE

17       "Moose::Meta::TypeConstraint" is a subclass of Class::MOP::Object.
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METHODS

20   Moose::Meta::TypeConstraint->new(%options)
21       This creates a new type constraint based on the provided %options:
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23       •   name
24
25           The constraint name. If a name is not provided, it will be set to
26           "__ANON__".
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28       •   parent
29
30           A "Moose::Meta::TypeConstraint" object which is the parent type for
31           the type being created. This is optional.
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33       •   constraint
34
35           This is the subroutine reference that implements the actual
36           constraint check. This defaults to a subroutine which always
37           returns true.
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39       •   message
40
41           A subroutine reference which is used to generate an error message
42           when the constraint fails. This is optional.
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44       •   coercion
45
46           A Moose::Meta::TypeCoercion object representing the coercions to
47           the type. This is optional.
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49       •   inlined
50
51           A subroutine which returns a string suitable for inlining this type
52           constraint. It will be called as a method on the type constraint
53           object, and will receive a single additional parameter, a variable
54           name to be tested (usually "$_" or "$_[0]".
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56           This is optional.
57
58       •   inline_environment
59
60           A hash reference of variables to close over. The keys are variables
61           names, and the values are references to the variables.
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63   $constraint->equals($type_name_or_object)
64       Returns true if the supplied name or type object is the same as the
65       current type.
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67   $constraint->is_subtype_of($type_name_or_object)
68       Returns true if the supplied name or type object is a parent of the
69       current type.
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71   $constraint->is_a_type_of($type_name_or_object)
72       Returns true if the given type is the same as the current type, or is a
73       parent of the current type. This is a shortcut for checking "equals"
74       and "is_subtype_of".
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76   $constraint->coerce($value)
77       This will attempt to coerce the value to the type. If the type does not
78       have any defined coercions this will throw an error.
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80       If no coercion can produce a value matching $constraint, the original
81       value is returned.
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83   $constraint->assert_coerce($value)
84       This method behaves just like "coerce", but if the result is not valid
85       according to $constraint, an error is thrown.
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87   $constraint->check($value)
88       Returns true if the given value passes the constraint for the type.
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90   $constraint->validate($value)
91       This is similar to "check". However, if the type is valid then the
92       method returns an explicit "undef". If the type is not valid, we call
93       "$self->get_message($value)" internally to generate an error message.
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95   $constraint->assert_valid($value)
96       Like "check" and "validate", this method checks whether $value is valid
97       under the constraint.  If it is, it will return true.  If it is not, an
98       exception will be thrown with the results of
99       "$self->get_message($value)".
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101   $constraint->name
102       Returns the type's name, as provided to the constructor.
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104   $constraint->parent
105       Returns the type's parent, as provided to the constructor, if any.
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107   $constraint->has_parent
108       Returns true if the type has a parent type.
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110   $constraint->parents
111       Returns all of the types parents as an list of type constraint objects.
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113   $constraint->constraint
114       Returns the type's constraint, as provided to the constructor.
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116   $constraint->get_message($value)
117       This generates a method for the given value. If the type does not have
118       an explicit message, we generate a default message.
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120   $constraint->has_message
121       Returns true if the type has a message.
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123   $constraint->message
124       Returns the type's message as a subroutine reference.
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126   $constraint->coercion
127       Returns the type's Moose::Meta::TypeCoercion object, if one exists.
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129   $constraint->has_coercion
130       Returns true if the type has a coercion.
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132   $constraint->can_be_inlined
133       Returns true if this type constraint can be inlined. A type constraint
134       which subtypes an inlinable constraint and does not add an additional
135       constraint "inherits" its parent type's inlining.
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137   $constraint->create_child_type(%options)
138       This returns a new type constraint of the same class using the provided
139       %options. The "parent" option will be the current type.
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141       This method exists so that subclasses of this class can override this
142       behavior and change how child types are created.
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BUGS

145       See "BUGS" in Moose for details on reporting bugs.
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AUTHORS

148       •   Stevan Little <stevan@cpan.org>
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150       •   Dave Rolsky <autarch@urth.org>
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152       •   Jesse Luehrs <doy@cpan.org>
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154       •   Shawn M Moore <sartak@cpan.org>
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156       •   יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
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158       •   Karen Etheridge <ether@cpan.org>
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160       •   Florian Ragwitz <rafl@debian.org>
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162       •   Hans Dieter Pearcey <hdp@cpan.org>
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164       •   Chris Prather <chris@prather.org>
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166       •   Matt S Trout <mstrout@cpan.org>
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169       This software is copyright (c) 2006 by Infinity Interactive, Inc.
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171       This is free software; you can redistribute it and/or modify it under
172       the same terms as the Perl 5 programming language system itself.
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176perl v5.32.1                      2021-01-27    Moose::Meta::TypeConstraint(3)
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