package Mouse::Meta::TypeConstraint;
-use strict;
-use warnings;
-use overload '""' => sub { shift->{name} }, # stringify to tc name
- fallback => 1;
+use Mouse::Util qw(:meta); # enables strict and warnings
sub new {
my $class = shift;
- my %args = @_;
- my $name = $args{name} || '__ANON__';
+ my %args = @_ == 1 ? %{$_[0]} : @_;
- my $check = $args{_compiled_type_constraint} or Carp::croak("missing _compiled_type_constraint");
- if (ref $check eq 'Mouse::Meta::TypeConstraint') {
- $check = $check->{_compiled_type_constraint};
+ $args{name} = '__ANON__' if !defined $args{name};
+
+ my $type_parameter;
+ if(defined $args{parent}) { # subtyping
+ %args = (%{$args{parent}}, %args);
+
+ # a child type must not inherit 'compiled_type_constraint'
+ # and 'hand_optimized_type_constraint' from the parent
+ delete $args{compiled_type_constraint}; # don't inherit it
+ delete $args{hand_optimized_type_constraint}; # don't inherit it
+
+ $type_parameter = $args{type_parameter};
+ if(defined(my $parent_tp = $args{parent}{type_parameter})) {
+ if($parent_tp != $type_parameter) {
+ $type_parameter->is_a_type_of($parent_tp)
+ or $class->throw_error(
+ "$type_parameter is not a subtype of $parent_tp",
+ );
+ }
+ else {
+ $type_parameter = undef;
+ }
+ }
+ }
+
+ my $check;
+
+ if($check = delete $args{optimized}) { # likely to be builtins
+ $args{hand_optimized_type_constraint} = $check;
+ $args{compiled_type_constraint} = $check;
+ }
+ elsif(defined $type_parameter) { # parameterizing
+ my $generator = $args{constraint_generator}
+ || $class->throw_error(
+ "The $args{name} constraint cannot be used,"
+ . " because $type_parameter doesn't subtype"
+ . " from a parameterizable type");
+
+ my $parameterized_check = $generator->($type_parameter);
+ if(defined(my $my_check = $args{constraint})) {
+ $check = sub {
+ return $parameterized_check->($_) && $my_check->($_);
+ };
+ }
+ else {
+ $check = $parameterized_check;
+ }
+ $args{constraint} = $check;
+ }
+ else { # common cases
+ $check = $args{constraint};
+ }
+
+ if(defined($check) && ref($check) ne 'CODE'){
+ $class->throw_error(
+ "Constraint for $args{name} is not a CODE reference");
}
- bless +{ name => $name, _compiled_type_constraint => $check }, $class;
+ my $self = bless \%args, $class;
+ $self->compile_type_constraint()
+ if !$args{hand_optimized_type_constraint};
+
+ if($args{type_constraints}) { # union types
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ # set undef for has_coercion()
+ $self->{_compiled_type_coercion} = undef;
+ last;
+ }
+ }
+ }
+
+ return $self;
+}
+
+sub create_child_type {
+ my $self = shift;
+ return ref($self)->new(@_, parent => $self);
}
-sub name { shift->{name} }
+sub name;
+sub parent;
+sub message;
+sub has_coercion;
+
+sub check;
+
+sub type_parameter;
+sub __is_parameterized;
+
+sub _compiled_type_constraint;
+sub _compiled_type_coercion;
+
+sub compile_type_constraint;
+
-sub check {
+sub _add_type_coercions { # ($self, @pairs)
my $self = shift;
- $self->{_compiled_type_constraint}->(@_);
+
+ if(exists $self->{type_constraints}){ # union type
+ $self->throw_error(
+ "Cannot add additional type coercions to Union types '$self'");
+ }
+
+ my $coercion_map = ($self->{coercion_map} ||= []);
+ my %has = map{ $_->[0]->name => undef } @{$coercion_map};
+
+ for(my $i = 0; $i < @_; $i++){
+ my $from = $_[ $i];
+ my $action = $_[++$i];
+
+ if(exists $has{$from}){
+ $self->throw_error("A coercion action already exists for '$from'");
+ }
+
+ my $type = Mouse::Util::TypeConstraints::find_or_parse_type_constraint($from)
+ or $self->throw_error(
+ "Could not find the type constraint ($from) to coerce from");
+
+ push @{$coercion_map}, [ $type => $action ];
+ }
+
+ $self->{_compiled_type_coercion} = undef;
+ return;
+}
+
+sub _compiled_type_coercion {
+ my($self) = @_;
+
+ my $coercion = $self->{_compiled_type_coercion};
+ return $coercion if defined $coercion;
+
+ if(!$self->{type_constraints}) {
+ my @coercions;
+ foreach my $pair(@{$self->{coercion_map}}) {
+ push @coercions,
+ [ $pair->[0]->_compiled_type_constraint, $pair->[1] ];
+ }
+
+ $coercion = sub {
+ my($thing) = @_;
+ foreach my $pair (@coercions) {
+ #my ($constraint, $converter) = @$pair;
+ if ($pair->[0]->($thing)) {
+ local $_ = $thing;
+ return $pair->[1]->($thing);
+ }
+ }
+ return $thing;
+ };
+ }
+ else { # for union type
+ my @coercions;
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ push @coercions, $type;
+ }
+ }
+ if(@coercions){
+ $coercion = sub {
+ my($thing) = @_;
+ foreach my $type(@coercions){
+ my $value = $type->coerce($thing);
+ return $value if $self->check($value);
+ }
+ return $thing;
+ };
+ }
+ }
+
+ return( $self->{_compiled_type_coercion} = $coercion );
+}
+
+sub coerce {
+ my $self = shift;
+ return $_[0] if $self->check(@_);
+
+ my $coercion = $self->_compiled_type_coercion
+ or $self->throw_error("Cannot coerce without a type coercion");
+ return $coercion->(@_);
+}
+
+sub get_message {
+ my ($self, $value) = @_;
+ if ( my $msg = $self->message ) {
+ local $_ = $value;
+ return $msg->($value);
+ }
+ else {
+ if(not defined $value) {
+ $value = 'undef';
+ }
+ elsif( ref($value) && defined(&overload::StrVal) ) {
+ $value = overload::StrVal($value);
+ }
+ return "Validation failed for '$self' with value $value";
+ }
+}
+
+sub is_a_type_of {
+ my($self, $other) = @_;
+
+ # ->is_a_type_of('__ANON__') is always false
+ return 0 if !ref($other) && $other eq '__ANON__';
+
+ (my $other_name = $other) =~ s/\s+//g;
+
+ return 1 if $self->name eq $other_name;
+
+ if(exists $self->{type_constraints}){ # union
+ foreach my $type(@{$self->{type_constraints}}) {
+ return 1 if $type->name eq $other_name;
+ }
+ }
+
+ for(my $p = $self->parent; defined $p; $p = $p->parent) {
+ return 1 if $p->name eq $other_name;
+ }
+
+ return 0;
+}
+
+# See also Moose::Meta::TypeConstraint::Parameterizable
+sub parameterize {
+ my($self, $param, $name) = @_;
+
+ if(!ref $param){
+ require Mouse::Util::TypeConstraints;
+ $param = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($param);
+ }
+
+ $name ||= sprintf '%s[%s]', $self->name, $param->name;
+ return Mouse::Meta::TypeConstraint->new(
+ name => $name,
+ parent => $self,
+ type_parameter => $param,
+ );
+}
+
+sub assert_valid {
+ my ($self, $value) = @_;
+
+ if(!$self->check($value)){
+ $self->throw_error($self->get_message($value));
+ }
+ return 1;
+}
+
+# overloading stuff
+
+sub _as_string { $_[0]->name } # overload ""
+sub _identity; # overload 0+
+
+sub _unite { # overload infix:<|>
+ my($lhs, $rhs) = @_;
+ require Mouse::Util::TypeConstraints;
+ return Mouse::Util::TypeConstraints::_find_or_create_union_type(
+ $lhs,
+ Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($rhs),
+ );
}
1;
=head1 NAME
-Mouse::Meta::TypeConstraint - The Mouse Type Constraint Metaclass
+Mouse::Meta::TypeConstraint - The Mouse Type Constraint metaclass
-=head1 DESCRIPTION
+=head1 VERSION
+
+This document describes Mouse version 0.88
-For the most part, the only time you will ever encounter an
-instance of this class is if you are doing some serious deep
-introspection. This API should not be considered final, but
-it is B<highly unlikely> that this will matter to a regular
-Mouse user.
+=head1 DESCRIPTION
-Don't use this.
+This class represents a type constraint, including built-in
+type constraints, union type constraints, parameterizable/
+parameterized type constraints, as well as custom type
+constraints
=head1 METHODS
-=over 4
+=over
+
+=item C<< Mouse::Meta::TypeConstraint->new(%options) >>
+
+=item C<< $constraint->name >>
-=item B<new>
+=item C<< $constraint->parent >>
-=item B<name>
+=item C<< $constraint->constraint >>
+
+=item C<< $constraint->has_coercion >>
+
+=item C<< $constraint->message >>
+
+=item C<< $constraint->is_a_type_of($name or $object) >>
+
+=item C<< $constraint->coerce($value) >>
+
+=item C<< $constraint->check($value) >>
+
+=item C<< $constraint->assert_valid($value) >>
+
+=item C<< $constraint->get_message($value) >>
+
+=item C<< $constraint->create_child_type(%options) >>
=back
+=head1 SEE ALSO
+
+L<Moose::Meta::TypeConstraint>
+
=cut
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