Moose::Cookbook::Snack::Types(3)			User Contributed Perl Documentation			  Moose::Cookbook::Snack::Types(3)

NAME

       Moose::Cookbook::Snack::Types - Snippets of code for using Types and Type Constraints

VERSION

       version 2.0604

SYNOPSIS

	 package Point;
	 use Moose;

	 has 'x' => ( isa => 'Int', is => 'ro' );
	 has 'y' => ( isa => 'Int', is => 'rw' );

	 package main;
	 use Try::Tiny;

	 my $point = try {
	     Point->new( x => 'fifty', y => 'forty' );
	 }
	 catch {
	     print "Oops: $_";
	 };

	 my $point;
	 my $xval	      = 'forty-two';
	 my $xattribute       = Point->meta->find_attribute_by_name('x');
	 my $xtype_constraint = $xattribute->type_constraint;

	 if ( $xtype_constraint->check($xval) ) {
	     $point = Point->new( x => $xval, y => 0 );
	 }
	 else {
	     print "Value: $xval is not an " . $xtype_constraint->name . "
";
	 }

DESCRIPTION

       This is the Point example from Moose::Cookbook::Basics::Point_AttributesAndSubclassing with type checking added.

       If we try to assign a string value to an attribute that is an "Int", Moose will die with an explicit error message. The error will include
       the attribute name, as well as the type constraint name and the value which failed the constraint check.

       We use Try::Tiny to catch this error message.

       Later, we get the Moose::Meta::TypeConstraint object from a Moose::Meta::Attribute and use the Moose::Meta::TypeConstraint to check a value
       directly.

SEE ALSO

       Moose::Cookbook::Basics::Point_AttributesAndSubclassing
       Moose::Utils::TypeConstraints
       Moose::Meta::Attribute

AUTHOR

       Moose is maintained by the Moose Cabal, along with the help of many contributors. See "CABAL" in Moose and "CONTRIBUTORS" in Moose for
       details.

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 by Infinity Interactive, Inc..

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.16.2							    2012-09-19					  Moose::Cookbook::Snack::Types(3)