'is' works with generic types correctly (initial implementation of reified generics)

stdlib/src/jet/typeinfo/TypeInfo.java

@@ -2,29 +2,49 @@ package jet.typeinfo;
 
 import jet.JetObject;
 
+import java.util.Arrays;
+
 /**
  * @author abreslav
  */
 public class TypeInfo<T> implements JetObject {
-
     private TypeInfo<?> typeInfo;
-    private TypeInfo<?> typeArgument;
-    private Class<T> theClass;
+    private final Class<T> theClass;
+    private final TypeInfo[] typeParameters;
 
     public TypeInfo(Class<T> theClass) {
         this.theClass = theClass;
+        this.typeParameters = null;
     }
 
-    private TypeInfo(TypeInfo<?> typeArgument) {
-        this.typeArgument = typeArgument;
+    public TypeInfo(Class<T> theClass, TypeInfo[] typeParameters) {
+        this.theClass = theClass;
+        this.typeParameters = typeParameters;
     }
 
     public boolean isInstance(Object obj) {
+        if (obj instanceof JetObject) {
+            return isSubtypeOf(((JetObject) obj).getTypeInfo());
+        }
         throw new UnsupportedOperationException(); // TODO
     }
 
     public boolean isSubtypeOf(TypeInfo<?> other) {
-        throw new UnsupportedOperationException(); // TODO
+        if (!theClass.isAssignableFrom(other.theClass)) {
+            return false;
+        }
+        if (typeParameters != null) {
+            if (other.typeParameters == null || other.typeParameters.length != typeParameters.length) {
+                throw new IllegalArgumentException("inconsistent type infos for the same class");
+            }
+            for (int i = 0; i < typeParameters.length; i++) {
+                // TODO handle variance here
+                if (!typeParameters [i].equals(other.typeParameters [i])) {
+                    return false;
+                }
+            }
+        }
+        return true;
     }
 
     @Override
@@ -35,4 +55,24 @@ public class TypeInfo<T> implements JetObject {
         }
         return typeInfo;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        TypeInfo typeInfo = (TypeInfo) o;
+
+        if (!theClass.equals(typeInfo.theClass)) return false;
+        if (!Arrays.equals(typeParameters, typeInfo.typeParameters)) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = theClass.hashCode();
+        result = 31 * result + (typeParameters != null ? Arrays.hashCode(typeParameters) : 0);
+        return result;
+    }
 }