$args{name} = '__ANON__' if !defined $args{name};
- if(defined $args{parent}) {
+ 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};
- delete $args{hand_optimized_type_constraint};
+ 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})) {
- delete $args{type_parameter} if $parent_tp == $args{type_parameter};
+ if($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 $args{optimized}) {
+ if($check = delete $args{optimized}) { # likely to be builtins
$args{hand_optimized_type_constraint} = $check;
$args{compiled_type_constraint} = $check;
}
- elsif(my $param = $args{type_parameter}) {
+ elsif(defined $type_parameter) { # parameterizing
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);
+ || $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 {
+ else { # common cases
$check = $args{constraint};
}
$self->compile_type_constraint()
if !$args{hand_optimized_type_constraint};
- if($args{type_constraints}) {
- $self->_compile_union_type_coercion();
+ if($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 $self;
}
"Cannot add additional type coercions to Union types '$self'");
}
- my $coercions = ($self->{coercion_map} ||= []);
- my %has = map{ $_->[0] => undef } @{$coercions};
+ my $coercion_map = ($self->{coercion_map} ||= []);
+ my %has = map{ $_->[0]->name => undef } @{$coercion_map};
for(my $i = 0; $i < @_; $i++){
my $from = $_[ $i];
or $self->throw_error(
"Could not find the type constraint ($from) to coerce from");
- push @{$coercions}, [ $type => $action ];
+ push @{$coercion_map}, [ $type => $action ];
}
- $self->_compile_type_coercion();
+ $self->{_compiled_type_coercion} = undef;
return;
}
-sub _compile_type_coercion {
+sub _compiled_type_coercion {
my($self) = @_;
- my @coercions = @{$self->{coercion_map}};
-
- $self->{_compiled_type_coercion} = sub {
- my($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 $coercion = $self->{_compiled_type_coercion};
+ return $coercion if defined $coercion;
- my @coercions;
- foreach my $type(@{$self->{type_constraints}}){
- if($type->has_coercion){
- push @coercions, $type;
+ if(!$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;
+ };
}
- if(@coercions){
- $self->{_compiled_type_coercion} = sub {
- my($thing) = @_;
- foreach my $type(@coercions){
- my $value = $type->coerce($thing);
- return $value if $self->check($value);
+ else { # for union type
+ my @coercions;
+ foreach my $type(@{$self->{type_constraints}}){
+ if($type->has_coercion){
+ push @coercions, $type;
}
- return $thing;
- };
+ }
+ if(@coercions){
+ $coercion = sub {
+ my($thing) = @_;
+ foreach my $type(@coercions){
+ my $value = $type->coerce($thing);
+ return $value if $self->check($value);
+ }
+ return $thing;
+ };
+ }
}
- return;
+
+ return( $self->{_compiled_type_coercion} = $coercion );
}
sub coerce {
my $self = shift;
return $_[0] if $self->check(@_);
- my $coercion = $self->{_compiled_type_coercion}
+ my $coercion = $self->_compiled_type_coercion
or $self->throw_error("Cannot coerce without a type coercion");
return $coercion->(@_);
}
return 1;
}
-sub _as_string { $_[0]->name } # overload ""
-sub _identity; # overload 0+
+# overloading stuff
+
+sub _as_string { $_[0]->name } # overload ""
+sub _identity; # overload 0+
sub _unite { # overload infix:<|>
my($lhs, $rhs) = @_;
=head1 VERSION
-This document describes Mouse version 0.81
+This document describes Mouse version 0.86
=head1 DESCRIPTION