Reflection: add KType.withNullability

2016-07-18 19:37:02 +03:00
parent f958483e56
commit 486ea62c72
4 changed files with 99 additions and 0 deletions
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@file:JvmName("KTypes")
+package kotlin.reflect
+
+import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.isFlexible
+import kotlin.reflect.jvm.internal.KTypeImpl
+
+/**
+ * Returns a new type with the same classifier, arguments and annotations as the given type, and with the given nullability.
+ */
+fun KType.withNullability(nullable: Boolean): KType {
+    if (isMarkedNullable) {
+        return if (nullable) this else KTypeImpl(TypeUtils.makeNotNullable((this as KTypeImpl).type)) { javaType }
+    }
+
+    // If the type is not marked nullable, it's either a non-null type or a platform type.
+    val kotlinType = (this as KTypeImpl).type
+    if (kotlinType.isFlexible()) return KTypeImpl(TypeUtils.makeNullableAsSpecified(kotlinType, nullable)) { javaType }
+
+    return if (!nullable) this else KTypeImpl(TypeUtils.makeNullable(kotlinType)) { javaType }
+}