typed exception when trying to mix in non-composable types

rakudo · May 27, 2012 · 6555ab1 · 6555ab1
1 parent 305e5ae
commit 6555ab1
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Showing 2 changed files with 13 additions and 5 deletions.
diff --git a/src/core/Exception.pm b/src/core/Exception.pm
@@ -714,6 +714,14 @@ my class X::Localizer::NoContainer is Exception {
     }
 }
 
+my class X::Mixin::NonComposable is Exception {
+    has $.target;
+    has $.rolish;
+    method message() {
+        "Cannot mix in non-composable type {$.rolish.^name} into object of type {$.target.^name}";
+    }
+}
+
 
 {
     my %c_ex;

diff --git a/src/core/operators.pm b/src/core/operators.pm
@@ -12,14 +12,14 @@ multi infix:<does>(Mu:D \$obj, Mu:U \$rolish) is rw {
     # XXX Mutability check.
     my $role := $rolish.HOW.archetypes.composable() ?? $rolish !!
                 $rolish.HOW.archetypes.composalizable() ?? $rolish.HOW.composalize($rolish) !!
-                die("Cannot mix in a non-composable type");
+                X::Mixin::NonComposable.new(:target($obj), :$rolish).throw;
     $obj.HOW.mixin($obj, $role).BUILD_LEAST_DERIVED({});
 }
 multi infix:<does>(Mu:D \$obj, Mu:U \$rolish, :$value! is parcel) is rw {
     # XXX Mutability check.
     my $role := $rolish.HOW.archetypes.composable() ?? $rolish !!
                 $rolish.HOW.archetypes.composalizable() ?? $rolish.HOW.composalize($rolish) !!
-                die("Cannot mix in a non-composable type");
+                X::Mixin::NonComposable.new(:target($obj), :$rolish).throw;
     my @attrs = $role.^attributes().grep: { .has_accessor };
     X::Role::Initialization.new().throw unless @attrs == 1;
     $obj.HOW.mixin($obj, $role).BUILD_LEAST_DERIVED({ @attrs[0].Str.substr(2) => $value });
@@ -39,13 +39,13 @@ proto infix:<but>(|$) { * }
 multi infix:<but>(Mu:D \$obj, Mu:U \$rolish) {
     my $role := $rolish.HOW.archetypes.composable() ?? $rolish !!
                 $rolish.HOW.archetypes.composalizable() ?? $rolish.HOW.composalize($rolish) !!
-                die("Cannot mix in a non-composable type");
+                X::Mixin::NonComposable.new(:target($obj), :$rolish).throw;
     $obj.HOW.mixin($obj.clone(), $role).BUILD_LEAST_DERIVED({});
 }
 multi infix:<but>(Mu:D \$obj, Mu:U \$rolish, :$value! is parcel) {
     my $role := $rolish.HOW.archetypes.composable() ?? $rolish !!
                 $rolish.HOW.archetypes.composalizable() ?? $rolish.HOW.composalize($rolish) !!
-                die("Cannot mix in a non-composable type");
+                X::Mixin::NonComposable.new(:target($obj), :$rolish).throw;
     my @attrs = $role.^attributes().grep: { .has_accessor };
     die(X::Role::Initialization.new())
         unless @attrs == 1;
@@ -60,7 +60,7 @@ multi infix:<but>(Mu:D \$obj, Mu:U \$rolish, :$value! is parcel) {
 multi infix:<but>(Mu:U \$obj, Mu:U \$rolish) {
     my $role := $rolish.HOW.archetypes.composable() ?? $rolish !!
                 $rolish.HOW.archetypes.composalizable() ?? $rolish.HOW.composalize($rolish) !!
-                die("Cannot mix in a non-composable type");
+                X::Mixin::NonComposable.new(:target($obj), :$rolish).throw;
     $obj.HOW.mixin($obj, $role);
 }
 multi infix:<but>(Mu \$obj, Mu:D $val) is rw {