File: //usr/local/share/man/man3/Type::Tiny::ConstrainedObject.3pm
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.\" ========================================================================
.\"
.IX Title "Type::Tiny::ConstrainedObject 3"
.TH Type::Tiny::ConstrainedObject 3 "2021-07-31" "perl v5.26.3" "User Contributed Perl Documentation"
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
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.nh
.SH "NAME"
Type::Tiny::ConstrainedObject \- shared behavour for Type::Tiny::Class, etc
.SH "STATUS"
.IX Header "STATUS"
This module is considered experiemental.
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
.SS "Methods"
.IX Subsection "Methods"
The following methods exist for Type::Tiny::Class, Type::Tiny::Role,
Type::Tiny::Duck, and any type constraints that inherit from
\&\f(CW\*(C`Object\*(C'\fR or \f(CW\*(C`Overload\*(C'\fR in Types::Standard.
.PP
These methods will also work for Type::Tiny::Intersection if at least
one of the types in the intersection provides these methods.
.PP
These methods will also work for Type::Tiny::Union if all of the types
in the union provide these methods.
.ie n .IP """stringifies_to($constraint)""" 4
.el .IP "\f(CWstringifies_to($constraint)\fR" 4
.IX Item "stringifies_to($constraint)"
Generates a new child type constraint which checks the object's
stringification against a constraint. For example:
.Sp
.Vb 2
\& my $type = Type::Tiny::Class\->new(class => \*(AqURI\*(Aq);
\& my $child = $type\->stringifies_to( StrMatch[qr/^http:/] );
\&
\& $child\->assert_valid( URI\->new("http://example.com/") );
.Ve
.Sp
In the above example, \f(CW$child\fR is a type constraint that
checks objects are blessed into (or inherit from) the \s-1URI\s0 class,
and when stringified (e.g. though overloading) the result
matches the regular expression \f(CW\*(C`qr/^http:/\*(C'\fR.
.Sp
\&\f(CW$constraint\fR may be a type constraint, something that
can be coerced to a type constraint (such as a coderef returning
a boolean), a string of Perl code operating on \f(CW$_\fR, or
a reference to a regular expression.
.Sp
So the following would work:
.Sp
.Vb 3
\& my $child = $type\->stringifies_to( sub { qr/^http:/ } );
\& my $child = $type\->stringifies_to( qr/^http:/ );
\& my $child = $type\->stringifies_to( \*(Aqm/^http:/\*(Aq );
\&
\& my $child = $type\->where(\*(Aq"$_" =~ /^http:/\*(Aq);
.Ve
.ie n .IP """numifies_to($constraint)""" 4
.el .IP "\f(CWnumifies_to($constraint)\fR" 4
.IX Item "numifies_to($constraint)"
The same as \f(CW\*(C`stringifies_to\*(C'\fR but checks numification.
.Sp
The following might be useful:
.Sp
.Vb 2
\& use Types::Standard qw(Int Overload);
\& my $IntLike = Int | Overload\->numifies_to(Int)
.Ve
.ie n .IP """with_attribute_values($attr1 => $constraint1, ...)""" 4
.el .IP "\f(CWwith_attribute_values($attr1 => $constraint1, ...)\fR" 4
.IX Item "with_attribute_values($attr1 => $constraint1, ...)"
This is best explained with an example:
.Sp
.Vb 2
\& use Types::Standard qw(InstanceOf StrMatch);
\& use Types::Common::Numeric qw(IntRange);
\&
\& my $person = InstanceOf[\*(AqLocal::Human\*(Aq];
\& my $woman = $person\->with_attribute_values(
\& gender => StrMatch[ qr/^F/i ],
\& age => IntRange[ 18 => () ],
\& );
\&
\& $woman\->assert_valid($alice);
.Ve
.Sp
This assertion will firstly check that \f(CW$alice\fR is a
Local::Human, then check that \f(CW\*(C`$alice\->gender\*(C'\fR starts
with an \*(L"F\*(R", and lastly check that \f(CW\*(C`$alice\->age\*(C'\fR is
an integer at least 18.
.Sp
Again, constraints can be type constraints, coderefs,
strings of Perl code, or regular expressions.
.Sp
Technically the \*(L"attributes\*(R" don't need to be Moo/Moose/Mouse
attributes, but any methods which can be called with no
parameters and return a scalar.
.SH "BUGS"
.IX Header "BUGS"
Please report any bugs to
<https://github.com/tobyink/p5\-type\-tiny/issues>.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Type::Tiny::Manual.
.PP
Type::Tiny.
.SH "AUTHOR"
.IX Header "AUTHOR"
Toby Inkster <tobyink@cpan.org>.
.SH "COPYRIGHT AND LICENCE"
.IX Header "COPYRIGHT AND LICENCE"
This software is copyright (c) 2019\-2021 by Toby Inkster.
.PP
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
.SH "DISCLAIMER OF WARRANTIES"
.IX Header "DISCLAIMER OF WARRANTIES"
\&\s-1THIS PACKAGE IS PROVIDED \*(L"AS IS\*(R" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.\s0