perldoc > Type::Tiny::Intersection

NAME
    Type::Tiny::Intersection - intersection type constraints

SYNOPSIS
    Using via the "&" operator overload:

      package Local::Stash {
        use Moo;
        use Types::Common qw( LowerCaseStr StrLength );

        has identifier => (
          is   => 'ro',
          isa  => (LowerCaseStr) & (StrLength[4, 8]),
        );
      }

      my $x = Local::Stash->new( data => {} );  # not ok
      my $y = Local::Stash->new( data => [] );  # not ok

    Note that it is a good idea to enclose each type being intersected in parentheses to avoid Perl
    thinking the "&" is the sigil for a coderef.

    Using Type::Tiny::Intersection's object-oriented interface:

      package Local::Stash {
        use Moo;
        use Types::Common qw( LowerCaseStr StrLength );
        use Type::Tiny::Intersection;

        my $ShortLcStr = Type::Tiny::Intersection->new(
          name             => 'AnyData',
          type_constraints => [ LowerCaseStr, StrLength[4, 8] ],
        );

        has identifier => (
          is   => 'ro',
          isa  => $ShortLcStr,
        );
      }

    Using Type::Utils's functional interface:

      package Local::Stash {
        use Moo;
        use Types::Common qw( LowerCaseStr StrLength );
        use Type::Utils;

        my $ShortLcStr = intersection ShortLcStr => [ LowerCaseStr, StrLength[4, 8] ];

        has identifier => (
          is   => 'ro',
          isa  => $ShortLcStr,
        );
      }

STATUS
    This module is covered by the Type-Tiny stability policy.

DESCRIPTION
    Intersection type constraints.

    Intersection type constraints are not often very useful. Consider the intersection of HashRef
    and ArrayRef. A value will only pass if it is both a hashref and an arrayref. Given that neither
    of those type constraints accept "undef" or overloaded objects, there is no possible value that
    can pass both.

    Which is not to say that intersections are never useful, but it happens quite rarely.

    This package inherits from Type::Tiny; see that for most documentation. Major differences are
    listed below:

  Constructor
    The "new" constructor from Type::Tiny still works, of course. But there is also:

    new_by_overload(%attributes)
        Like the "new" constructor, but will sometimes return another type constraint which is not
        strictly an instance of Type::Tiny::Intersection, but still encapsulates the same meaning.
        This constructor is used by Type::Tiny's overloading of the "&" operator.

  Attributes
    "type_constraints"
        Arrayref of type constraints.

        When passed to the constructor, if any of the type constraints in the intersection is itself
        an intersection type constraint, this is "exploded" into the new intersection.

    "constraint"
        Unlike Type::Tiny, you *cannot* pass a constraint coderef to the constructor. Instead rely
        on the default.

    "inlined"
        Unlike Type::Tiny, you *cannot* pass an inlining coderef to the constructor. Instead rely on
        the default.

    "parent"
        Unlike Type::Tiny, you *cannot* pass an inlining coderef to the constructor. A parent will
        instead be automatically calculated.

        (Technically any of the types in the intersection could be treated as a parent type; we
        choose the first arbitrarily.)

  Methods
    stringifies_to($constraint)
        See Type::Tiny::ConstrainedObject.

    numifies_to($constraint)
        See Type::Tiny::ConstrainedObject.

    "with_attribute_values($attr1 => $constraint1, ...)"
        See Type::Tiny::ConstrainedObject.

  Overloading
    *   Arrayrefification calls "type_constraints".

BUGS
    Please report any bugs to <https://github.com/tobyink/p5-type-tiny/issues>.

SEE ALSO
    Type::Tiny::Manual.

    Type::Tiny.

    MooseX::Meta::TypeConstraint::Intersection.

AUTHOR
    Toby Inkster <tobyink AT cpan.org>.

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.