NAME

Type::Nano - simple type constraint library for testing

SYNOPSIS

  use Type::Nano qw(Int);
  
  Int->check("42");  # true

RATIONALE

This is a really basic implementation of Type::API::Constraint for testing modules that make use of type constraints.

I'll stress that this module is only intended for use in testing. It was created to eliminate Type::Tie's testing dependency on Types::Standard. If your code supports Type::Nano, then your code should also automatically support Type::Tiny, Specio, MooseX::Types, and MouseX::Types with no extra effort. (Of course, some of those libraries do have some more features you may want to make extra effort to use! Inlining, for example.)

Type::Nano is not recommended for use in regular application code. Type::Tiny while bigger than Type::Nano, will be much faster at runtime, and offers better integration with Moo, Moose, Mouse, and a wide variety of other tools. Use that instead.

All that having been said, Type::Nano is compatible with: Type::Tie, Moo, Type::Tiny (e.g. you can use Type::Tiny's implementation of ArrayRef and Type::Nano's implementation of Int, and combine them as ArrayRef[Int]), Class::XSConstructor, and Variable::Declaration.

DESCRIPTION

Object-Oriented Interface

Constructor

Type::Nano->new(%parameters)

The constructor supports named parameters called name (a string), constraint (a coderef expected to return a boolean), and parent (a blessed Type::Nano object). Any other parameters passed to the constructor will be stored in the blessed hashref returned, but are ignored by Type::Nano. (Subclasses may use them.)

Methods

Types support the following methods:

$type->check($value)

Checks the value against the constraint; returns a boolean.

$type->get_message($failing_value)

Returns an error message. Does not check the value.

Types overload &{} to do something like:

  $type->check($value) or croak($type->get_message($value))

Exports

This module optionally exports the following type constraints:

• Any

• Defined

• Undef

• Ref

• ArrayRef

• HashRef

• CodeRef

• Object

• Str

• Bool

• Num

• Int

It also optionally exports the following functions for creating new type constraints:

• type $name, $coderef or type $coderef

• class_type $class

• role_type $role

• duck_type $name, \@methods or duck_type \@methods

• enum $name, \@values or enum \@values

• union $name, \@types or union \@types

• intersection $name, \@types or intersection \@types

SEE ALSO

Type::API.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2018-2019, 2022 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.

cpanm Type::API

perl -MCPAN -e shell
install Type::API