package Mouse::Meta::TypeConstraint;
-use strict;
-use warnings;
-
-use overload
- '""' => sub { shift->{name} }, # stringify to tc name
- fallback => 1;
-
-use Carp qw(confess);
-use Scalar::Util qw(blessed reftype);
-
-use Mouse::Util qw(:meta);
-
-my $null_check = sub { 1 };
+use Mouse::Util qw(:meta); # enables strict and warnings
sub new {
- my($class, %args) = @_;
+ my $class = shift;
+ my %args = @_ == 1 ? %{$_[0]} : @_;
$args{name} = '__ANON__' if !defined $args{name};
- my $check = $args{_compiled_type_constraint} || $args{constraint};
+ if(defined $args{parent}) {
+ %args = (%{$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};
+ delete $args{hand_optimized_type_constraint};
+ }
+
+ my $check;
- if(blessed($check)){
- Carp::cluck("'constraint' must be a CODE reference");
- $check = $check->{_compiled_type_constraint};
+ if($check = delete $args{optimized}) {
+ $args{hand_optimized_type_constraint} = $check;
+ $args{compiled_type_constraint} = $check;
+ }
+ elsif(my $param = $args{type_parameter}) {
+ my $generator = $args{constraint_generator}
+ || $class->throw_error("The $args{name} constraint cannot be used,"
+ . " because $param doesn't subtype from a parameterizable type");
+ # it must be 'constraint'
+ $check = $args{constraint} = $generator->($param);
+ }
+ else {
+ $check = $args{constraint};
}
if(defined($check) && ref($check) ne 'CODE'){
- confess("Type constraint for $args{name} is not a CODE reference");
+ $class->throw_error(
+ "Constraint for $args{name} is not a CODE reference");
}
my $self = bless \%args, $class;
- $self->{_compiled_type_constraint} ||= $self->_compile();
+ $self->compile_type_constraint()
+ if !$args{hand_optimized_type_constraint};
+ if($args{type_constraints}) {
+ $self->_compile_union_type_coercion();
+ }
return $self;
}
-sub create_child_type{
+sub create_child_type {
my $self = shift;
- # XXX: FIXME
- return ref($self)->new(
- %{$self}, # pass the inherit parent attributes
- _compiled_type_constraint => undef, # ... other than compiled type constraint
- @_, # ... and args
- parent => $self # ... and the parent
- );
+ return ref($self)->new(@_, parent => $self);
}
-sub name { $_[0]->{name} }
-sub parent { $_[0]->{parent} }
-sub message { $_[0]->{message} }
+sub name;
+sub parent;
+sub message;
+sub has_coercion;
-sub check {
+sub check;
+
+sub type_parameter;
+sub __is_parameterized;
+
+sub _compiled_type_constraint;
+sub _compiled_type_coercion;
+
+sub compile_type_constraint;
+
+
+sub _add_type_coercions { # ($self, @pairs)
my $self = shift;
- $self->{_compiled_type_constraint}->(@_);
-}
-sub validate {
- my ($self, $value) = @_;
- if ($self->{_compiled_type_constraint}->($value)) {
- return undef;
+ if(exists $self->{type_constraints}){ # union type
+ $self->throw_error(
+ "Cannot add additional type coercions to Union types '$self'");
}
- else {
- $self->get_message($value);
+
+ my $coercions = ($self->{coercion_map} ||= []);
+ my %has = map{ $_->[0] => undef } @{$coercions};
+
+ 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 @{$coercions}, [ $type => $action ];
}
+
+ $self->_compile_type_coercion();
+ return;
}
-sub assert_valid {
- my ($self, $value) = @_;
+sub _compile_type_coercion {
+ my($self) = @_;
- my $error = $self->validate($value);
- return 1 if ! defined $error;
+ my @coercions = @{$self->{coercion_map}};
- confess($error);
+ $self->{_compiled_type_coercion} = sub {
+ my($thing) = @_;
+ foreach my $pair (@coercions) {
+ #my ($constraint, $converter) = @$pair;
+ if ($pair->[0]->check($thing)) {
+ local $_ = $thing;
+ return $pair->[1]->($thing);
+ }
+ }
+ return $thing;
+ };
+ return;
+}
+
+sub _compile_union_type_coercion {
+ my($self) = @_;
+
+ my @coercions;
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ push @coercions, $type;
+ }
+ }
+ if(@coercions){
+ $self->{_compiled_type_coercion} = sub {
+ my($thing) = @_;
+ foreach my $type(@coercions){
+ my $value = $type->coerce($thing);
+ return $value if $self->check($value);
+ }
+ return $thing;
+ };
+ }
+ return;
+}
+
+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 {
return $msg->($value);
}
else {
- $value = ( defined $value ? overload::StrVal($value) : 'undef' );
- return
- "Validation failed for '"
- . $self->name
- . "' failed with value $value";
+ if(not defined $value) {
+ $value = 'undef';
+ }
+ elsif( ref($value) && defined(&overload::StrVal) ) {
+ $value = overload::StrVal($value);
+ }
+ return "Validation failed for '$self' with value $value";
}
}
-sub is_a_type_of{
+sub is_a_type_of {
my($self, $other) = @_;
# ->is_a_type_of('__ANON__') is always false
- return 0 if !blessed($other) && $other eq '__ANON__';
+ return 0 if !ref($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}}){
+ foreach my $type(@{$self->{type_constraints}}) {
return 1 if $type->name eq $other_name;
}
}
- for(my $parent = $self->parent; defined $parent; $parent = $parent->parent){
- return 1 if $parent->name eq $other_name;
+ for(my $p = $self->parent; defined $p; $p = $p->parent) {
+ return 1 if $p->name eq $other_name;
}
return 0;
}
-sub _compile{
- my($self) = @_;
+# See also Moose::Meta::TypeConstraint::Parameterizable
+sub parameterize{
+ my($self, $param, $name) = @_;
- # add parents first
- my @checks;
- for(my $parent = $self->parent; defined $parent; $parent = $parent->parent){
- if($parent->{constraint}){
- push @checks, $parent->{constraint};
- }
- elsif($parent->{_compiled_type_constraint} && $parent->{_compiled_type_constraint} != $null_check){
- # hand-optimized constraint
- push @checks, $parent->{_compiled_type_constraint};
- last;
- }
- }
- # then add child
- if($self->{constraint}){
- push @checks, $self->{constraint};
+ if(!ref $param){
+ require Mouse::Util::TypeConstraints;
+ $param = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($param);
}
- if(@checks == 0){
- return $null_check;
- }
- elsif(@checks == 1){
- my $c = $checks[0];
- return sub{
- my(@args) = @_;
- local $_ = $args[0];
- return $c->(@args);
- };
- }
- else{
- return sub{
- my(@args) = @_;
- local $_ = $args[0];
- foreach my $c(@checks){
- return undef if !$c->(@args);
- }
- return 1;
- };
+ $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;
+}
+
+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_parse_type_constraint(
+ " $lhs | $rhs",
+ );
}
1;
Mouse::Meta::TypeConstraint - The Mouse Type Constraint metaclass
-=head1 DESCRIPTION
+=head1 VERSION
+
+This document describes Mouse version 0.77
-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 C<< $constraint->parent >>
+
+=item C<< $constraint->constraint >>
+
+=item C<< $constraint->has_coercion >>
+
+=item C<< $constraint->message >>
+
+=item C<< $constraint->is_a_subtype_of($name or $object) >>
+
+=item C<< $constraint->coerce($value) >>
+
+=item C<< $constraint->check($value) >>
+
+=item C<< $constraint->assert_valid($value) >>
-=item B<new>
+=item C<< $constraint->get_message($value) >>
-=item B<name>
+=item C<< $constraint->create_child_type(%options) >>
=back
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