From: Daisuke Maki <dmaki@cpan.org>
Date: Sat, 7 Mar 2009 08:40:26 +0000 (+0000)
Subject: I want parameterized types... I want it!
X-Git-Tag: 0.19~7
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=commitdiff_plain;h=315b97c2ab833293683baad8c1773fd0d48ab5a4

I want parameterized types... I want it!
---

diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm
index 4387bcd..4d312da 100644
--- a/lib/Mouse/Meta/Attribute.pm
+++ b/lib/Mouse/Meta/Attribute.pm
@@ -191,6 +191,58 @@ sub generate_handles {
     return \%method_map;
 }
 
+our $optimized_constraints;
+sub _build_type_constraint {
+    my $spec = shift;
+    local $optimized_constraints ||= Mouse::Util::TypeConstraints->optimized_constraints;
+    my $code;
+    if ($spec =~ /^([^\[]+)\[(.+)\]$/) {
+        # parameterized
+        my $constraint = $1;
+        my $param      = $2;
+        my $parent     = _build_type_constraint($constraint);
+        my $child      = _build_type_constraint($param);
+        if ($constraint eq 'ArrayRef') {
+            my $code_str = 
+                "sub {\n" .
+                "    if (\$parent->(\$_)) {\n" .
+                "        foreach my \$e (@\$_) {\n" .
+                "            local \$_ = \$e;\n" .
+                "            return () unless \$child->(\$_);\n" .
+                "        }\n" .
+                "        return 1;\n" .
+                "    }\n" .
+                "    return ();\n" .
+                "};\n"
+            ;
+            $code = eval $code_str or Carp::confess($@);
+        } elsif ($constraint eq 'HashRef') {
+            my $code_str = 
+                "sub {\n" .
+                "    if (\$parent->(\$_)) {\n" .
+                "        foreach my \$e (values %\$_) {\n" .
+                "            local \$_ = \$e;\n" .
+                "            return () unless \$child->(\$_);\n" .
+                "        }\n" .
+                "        return 1;\n" .
+                "    }\n" .
+                "    return ();\n" .
+                "};\n"
+            ;
+            $code = eval $code_str or Carp::confess($@);
+        } else {
+            Carp::confess("Support for parameterized types other than ArrayRef or HashRef is not implemented yet");
+        }
+    } else {
+        $code = $optimized_constraints->{ $spec };
+        if (! $code) {
+            $code = sub { Scalar::Util::blessed($_) && $_->isa($spec) };
+            $optimized_constraints->{$spec} = $code;
+        }
+    }
+    return $code;
+}
+
 sub create {
     my ($self, $class, $name, %args) = @_;
 
@@ -204,24 +256,22 @@ sub create {
         if exists $args{coerce};
 
     if (exists $args{isa}) {
-        confess "Mouse does not yet support parameterized types (rt.cpan.org #39795)"
-            if $args{isa} =~ /\[.*\]/;
+        warn "Got isa => $args{isa}, but Mouse does not yet support parameterized types for containers other than ArrayRef and HashRef (rt.cpan.org #39795)"
+            if $args{isa} =~ /^([^\[]+)\[.+\]$/ &&
+               $1 ne 'ArrayRef' &&
+               $1 ne 'HashRef';
 
         my $type_constraint = delete $args{isa};
         $type_constraint =~ s/\s//g;
         my @type_constraints = split /\|/, $type_constraint;
 
         my $code;
-        my $optimized_constraints = Mouse::Util::TypeConstraints->optimized_constraints;
         if (@type_constraints == 1) {
-            $code = $optimized_constraints->{$type_constraints[0]} ||
-                sub { Scalar::Util::blessed($_) && $_->isa($type_constraints[0]) };
+            $code = _build_type_constraint($type_constraints[0]);
             $args{type_constraint} = $type_constraints[0];
         } else {
             my @code_list = map {
-                my $type = $_;
-                $optimized_constraints->{$type} ||
-                    sub { Scalar::Util::blessed($_) && $_->isa($type) }
+                _build_type_constraint($_)
             } @type_constraints;
             $code = sub {
                 for my $code (@code_list) {
diff --git a/t/043-parameterized-type.t b/t/043-parameterized-type.t
index 8bc1d98..7bc3edb 100644
--- a/t/043-parameterized-type.t
+++ b/t/043-parameterized-type.t
@@ -1,13 +1,11 @@
 #!/usr/bin/env perl
 use strict;
 use warnings;
-use Test::More tests => 1;
+use Test::More tests => 7;
 use Test::Exception;
 
-TODO: {
-    local $TODO = "Mouse does not support parameterized types yet";
-
-    eval {
+{
+    {
         package Foo;
         use Mouse;
 
@@ -15,8 +13,44 @@ TODO: {
             is  => 'ro',
             isa => 'HashRef[Int]',
         );
+
+        has bar => (
+            is  => 'ro',
+            isa => 'ArrayRef[Int]',
+        );
+
+        has 'complex' => (
+            is => 'rw',
+            isa => 'ArrayRef[HashRef[Int]]'
+        );
     };
 
     ok(Foo->meta->has_attribute('foo'));
-};
+
+    lives_and {
+        my $hash = { a => 1, b => 2, c => 3 };
+        my $array = [ 1, 2, 3 ];
+        my $complex = [ { a => 1, b => 1 }, { c => 2, d => 2} ];
+        my $foo = Foo->new(foo => $hash, bar => $array, complex => $complex);
+
+        is_deeply($foo->foo(), $hash, "foo is a proper hash");
+        is_deeply($foo->bar(), $array, "bar is a proper array");
+        is_deeply($foo->complex(), $complex, "complex is a proper ... structure");
+    } "Parameterized constraints work";
+
+    # check bad args
+    throws_ok {
+        Foo->new( foo => { a => 'b' });
+    } qr/Attribute \(foo\) does not pass the type constraint because: Validation failed for 'HashRef\[Int\]' failed with value/, "Bad args for hash throws an exception";
+
+    throws_ok {
+        Foo->new( bar => [ a => 'b' ]);
+    } qr/Attribute \(bar\) does not pass the type constraint because: Validation failed for 'ArrayRef\[Int\]' failed with value/, "Bad args for array throws an exception";
+
+    throws_ok {
+        Foo->new( complex => [ { a => 1, b => 1 }, { c => "d", e => "f" } ] )
+    } qr/Attribute \(complex\) does not pass the type constraint because: Validation failed for 'ArrayRef\[HashRef\[Int\]\]' failed with value/, "Bad args for complex types throws an exception";
+}
+
+