# Types::TypeTiny - type constraints used internally by Type::Tiny - perldoc - [phpMan] ## NAME [Types::TypeTiny](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ATypeTiny/markdown) - type constraints used internally by [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) ## STATUS This module is covered by the Type-Tiny stability policy. The BoolLike type is currently unstable. ## DESCRIPTION Dogfooding. This isn't a real [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown)-based type library; that would involve too much circularity. But it exports some type constraints which, while designed for use within [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown), may be more generally useful. ### Types * StringLike Accepts strings and objects overloading stringification. * BoolLike Accepts undef, "", 0, 1; accepts any blessed object overloading "bool"; accepts any blessed object overloading "0+" to return 0 or 1. (Needs to actually call the overloaded operation to check that.) Warning: an object which overloads "0+" without also turning on overload fallbacks may actually be useless as a practical boolean. But some common objects such as [JSON::PP](https://www.chedong.com/phpMan.php/perldoc/JSON%3A%3APP/markdown)'s booleans overload "0+" instead of overloading "bool" (thankfully with fallbacks enabled!) so we do need to support this. The intention of this type is to be a version of Bool which also accepts common boolean objects such as [JSON::PP::Boolean](https://www.chedong.com/phpMan.php/perldoc/JSON%3A%3APP%3A%3ABoolean/markdown). It is currently unstable and the exact definition of the type may change to better implement that intended functionality. * HashLike[`a] Accepts hashrefs and objects overloading hashification. Since [Types::TypeTiny](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ATypeTiny/markdown) 1.012, may be parameterized with another type constraint like HashLike[Int]. * ArrayLike[`a] Accepts arrayrefs and objects overloading arrayfication. Since [Types::TypeTiny](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ATypeTiny/markdown) 1.012, may be parameterized with another type constraint like ArrayLike[Int]. * CodeLike Accepts coderefs and objects overloading codification. * TypeTiny Accepts blessed [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) objects. * _ForeignTypeConstraint Any reference which to_TypeTiny recognizes as something that can be coerced to a [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) object. Yes, the underscore is included. ### Coercion Functions ### to_TypeTiny Promotes (or "demotes" if you prefer) a "foreign" type constraint to a [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) object. Can handle: * Moose types (including [Moose::Meta::TypeConstraint](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint/markdown) objects and [MooseX::Types::TypeDecorator](https://www.chedong.com/phpMan.php/perldoc/MooseX%3A%3ATypes%3A%3ATypeDecorator/markdown) objects). * Mouse types (including [Mouse::Meta::TypeConstraint](https://www.chedong.com/phpMan.php/perldoc/Mouse%3A%3AMeta%3A%3ATypeConstraint/markdown) objects). * [Validation::Class](https://www.chedong.com/phpMan.php/perldoc/Validation%3A%3AClass/markdown) and [Validation::Class::Simple](https://www.chedong.com/phpMan.php/perldoc/Validation%3A%3AClass%3A%3ASimple/markdown) objects. * Types built using [Type::Library::Compiler](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary%3A%3ACompiler/markdown). * Any object which provides "check" and "get_message" methods. (This includes Specio and [Type::Nano](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ANano/markdown) types.) If the object provides "has_coercion" and coerce methods, these will be used to handle quoting. If the object provides "can_be_inlined" and "inline_check" methods, these will be used to handling inlining. If the object provides a "name" method, this will be assumed to return the type name. * Coderefs (but not blessed coderefs or objects overloading "&{}" unless they provide the methods described above!) Coderefs are expected to return true iff $_ passes the constraint. If $_ fails the type constraint, they may either return false, or die with a helpful error message. * [Sub::Quote](https://www.chedong.com/phpMan.php/perldoc/Sub%3A%3AQuote/markdown)-enabled coderefs. These are handled the same way as above, but [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown) will consult [Sub::Quote](https://www.chedong.com/phpMan.php/perldoc/Sub%3A%3AQuote/markdown) to determine if they can be inlined. ### Methods These are implemented so that "[Types::TypeTiny](https://www.chedong.com/phpMan.php/perldoc/Types%3A%3ATypeTiny/markdown)->meta->get_type($foo)" works, for rough compatibility with a real [Type::Library](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ALibrary/markdown) type library. "meta" "type_names" ### get_type ### has_type "coercion_names" ### get_coercion ### has_coercion ## BUGS Please report any bugs to <>. ## SEE ALSO [Type::Tiny](https://www.chedong.com/phpMan.php/perldoc/Type%3A%3ATiny/markdown). ## AUTHOR Toby Inkster <>. ## COPYRIGHT AND LICENCE This software is copyright (c) 2013-2014, 2017-2023 by Toby Inkster. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. ## DISCLAIMER OF WARRANTIES THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.