package MooseX::Meta::TypeConstraint::Structured;
-use 5.8.8; ## Minimum tested Perl Version
use Moose;
-use Moose::Util::TypeConstraints;
-
+use Moose::Util::TypeConstraints ();
extends 'Moose::Meta::TypeConstraint';
-our $AUTHORITY = 'cpan:JJNAPIORK';
-
=head1 NAME
-MooseX::Meta::TypeConstraint::Structured - Structured Type Constraints
-
-=head1 VERSION
-
-0.01
-
-=cut
-
-our $VERSION = '0.01';
+MooseX::Meta::TypeConstraint::Structured - Structured type constraints.
=head1 DESCRIPTION
-Structured type constraints let you assign an internal pattern of type
-constraints to a 'container' constraint. The goal is to make it easier to
-declare constraints like "ArrayRef[Int, Int, Str]" where the constraint is an
-ArrayRef of three elements and the internal constraint on the three is Int, Int
-and Str.
-
-=head1 SUBTYPES
-
-The following subtypes and coercions are defined in this class.
-
-=head2 MooseX::Meta::TypeConstraint::Structured::Signature
+A structure is a set of L<Moose::Meta::TypeConstraint> that are 'aggregated' in
+such a way as that they are all applied to an incoming list of arguments. The
+idea here is that a Type Constraint could be something like, "An Int followed by
+an Int and then a Str" and that this could be done so with a declaration like:
-This is a type constraint to normalize the incoming L</signature>.
-
-=cut
-
-subtype 'MooseX::Meta::TypeConstraint::Structured::Signature',
- as 'HashRef[Object]',
- where {
- my %signature = %$_;
- foreach my $key (keys %signature) {
- $signature{$key}->isa('Moose::Meta::TypeConstraint');
- } 1;
- };
-
-coerce 'MooseX::Meta::TypeConstraint::Structured::Signature',
- from 'ArrayRef[Object]',
- via {
- my @signature = @$_;
- my %hashed_signature = map { $_ => $signature[$_] } 0..$#signature;
- \%hashed_signature;
- };
+ Tuple[Int,Int,Str]; ## Example syntax
+
+So a structure is a list of Type constraints (the "Int,Int,Str" in the above
+example) which are intended to function together.
=head1 ATTRIBUTES
This class defines the following attributes.
-=head2 signature
+=head2 type_constraints
-This is a signature of internal contraints for the contents of the outer
-contraint container.
+A list of L<Moose::Meta::TypeConstraint> objects.
=cut
-has 'signature' => (
+has 'type_constraints' => (
is=>'ro',
- isa=>'MooseX::Meta::TypeConstraint::Structured::Signature',
- coerce=>1,
- required=>1,
+ isa=>'Ref',
+ predicate=>'has_type_constraints',
);
-=head1 METHODS
+=head2 constraint_generator
-This class defines the following methods.
+A subref or closure that contains the way we validate incoming values against
+a set of type constraints.
-=head2 _normalize_args
+=cut
-Get arguments into a known state or die trying. Ideally we try to make this
-into a HashRef so we can match it up with the L</signature> HashRef.
+has 'constraint_generator' => (is=>'ro', isa=>'CodeRef');
-=cut
+=head1 METHODS
-sub _normalize_args {
- my ($self, $args) = @_;
- if(defined $args) {
- if(ref $args eq 'ARRAY') {
- return map { $_ => $args->[$_] } (0..$#$args);
- } elsif (ref $args eq 'HASH') {
- return %$args;
- } else {
- confess 'Signature must be a reference';
- }
- } else {
- confess 'Signature cannot be empty';
- }
-}
-
-=head2 constraint
+This class defines the following methods.
+
+=head2 generate_constraint_for ($type_constraints)
-The constraint is basically validating the L</signature> against the incoming
+Given some type constraints, use them to generate validation rules for an ref
+of values (to be passed at check time)
=cut
-sub constraint {
- my $self = shift;
+sub generate_constraint_for {
+ my ($self, $type_constraints) = @_;
return sub {
- my %args = $self->_normalize_args(shift);
- foreach my $idx (keys %{$self->signature}) {
- my $type_constraint = $self->signature->{$idx};
- if(my $error = $type_constraint->validate($args{$idx})) {
- confess $error;
- }
- } 1;
+ my $constraint_generator = $self->constraint_generator;
+ return $constraint_generator->($type_constraints, @_);
};
}
-=head2 equals
+=head2 parameterize (@type_constraints)
-modifier to make sure equals descends into the L</signature>
+Given a ref of type constraints, create a structured type.
=cut
-around 'equals' => sub {
- my ($equals, $self, $compared_type_constraint) = @_;
-
- ## Make sure we are comparing typeconstraints of the same base class
- return unless $compared_type_constraint->isa(__PACKAGE__);
-
- ## Make sure the base equals is also good
- return unless $self->$equals($compared_type_constraint);
-
- ## Make sure the signatures match
- return unless $self->signature_equals($compared_type_constraint);
-
- ## If we get this far, the two are equal
- return 1;
-};
+sub parameterize {
+ my ($self, @type_constraints) = @_;
+ my $name = $self->name .'['. join(',', map {"$_"} @type_constraints) .']';
+
+ return __PACKAGE__->new(
+ name => $name,
+ parent => $self,
+ type_constraints => \@type_constraints,
+ constraint_generator => $self->constraint_generator || sub {
+ my $tc = shift @_;
+ my $merged_tc = [@$tc, @{$self->parent->type_constraints}];
+ $self->constraint->($merged_tc, @_);
+ },
+ );
+}
-=head2 signature_equals
+=head2 compile_type_constraint
-Check that the signature equals another signature.
+hook into compile_type_constraint so we can set the correct validation rules.
=cut
-sub signature_equals {
- my ($self, $compared_type_constraint) = @_;
+around 'compile_type_constraint' => sub {
+ my ($compile_type_constraint, $self, @args) = @_;
- foreach my $idx (keys %{$self->signature}) {
- my $this = $self->signature->{$idx};
- my $that = $compared_type_constraint->signature->{$idx};
- return unless $this->equals($that);
+ if($self->has_type_constraints) {
+ my $type_constraints = $self->type_constraints;
+ my $constraint = $self->generate_constraint_for($type_constraints);
+ $self->_set_constraint($constraint);
}
-
- return 1;
-}
+
+ return $self->$compile_type_constraint(@args);
+};
+
+=head1 SEE ALSO
+
+The following modules or resources may be of interest.
+
+L<Moose>, L<Moose::Meta::TypeConstraint>
=head1 AUTHOR
-John James Napiorkowski <jjnapiork@cpan.org>
+John Napiorkowski, C<< <jjnapiork@cpan.org> >>
-=head1 LICENSE
+=head1 COPYRIGHT & LICENSE
-You may distribute this code under the same terms as Perl itself.
+This program is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
=cut
-no Moose; 1;
+1;
\ No newline at end of file