Compiler: fixed restriction of alias against generic. Fixes #3261

crystal-lang · Sep 6, 2016 · e9ab595 · e9ab595
1 parent 9130ec7
commit e9ab595
Showing 2 changed files with 62 additions and 0 deletions.
diff --git a/spec/compiler/codegen/alias_spec.cr b/spec/compiler/codegen/alias_spec.cr
@@ -136,4 +136,42 @@ describe "Code gen: alias" do
       end
       )).to_i.should eq(2)
   end
+
+  it "overloads alias against generic (1) (#3261)" do
+    run(%(
+      class Foo(T)
+      end
+
+      alias FooString = Foo(String)
+
+      def take(foo : Foo(String))
+        1
+      end
+
+      def take(foo : FooString)
+        2
+      end
+
+      take(Foo(String).new)
+      ), inject_primitives: false).to_i.should eq(2)
+  end
+
+  it "overloads alias against generic (2) (#3261)" do
+    run(%(
+      class Foo(T)
+      end
+
+      alias FooString = Foo(String)
+
+      def take(foo : FooString)
+        2
+      end
+
+      def take(foo : Foo(String))
+        1
+      end
+
+      take(Foo(String).new)
+      ), inject_primitives: false).to_i.should eq(1)
+  end
 end
diff --git a/src/compiler/crystal/semantic/restrictions.cr b/src/compiler/crystal/semantic/restrictions.cr
@@ -224,6 +224,18 @@ module Crystal
       other.types.any? { |o| self.restriction_of?(o, owner) }
     end
 
+    def restriction_of?(other : Generic, owner)
+      self_type = owner.lookup_path(self)
+      if self_type
+        other_type = owner.lookup_type?(other)
+        if other_type
+          return self_type.restriction_of?(other_type, owner)
+        end
+      end
+
+      false
+    end
+
     def restriction_of?(other, owner)
       false
     end
@@ -240,6 +252,18 @@ module Crystal
   end
 
   class Generic
+    def restriction_of?(other : Path, owner)
+      other_type = owner.lookup_type?(self)
+      if other_type
+        self_type = owner.lookup_path(other)
+        if self_type
+          return self_type.restriction_of?(other_type, owner)
+        end
+      end
+
+      false
+    end
+
     def restriction_of?(other : Generic, owner)
       return true if self == other
       return false unless name == other.name && type_vars.size == other.type_vars.size