| // Copyright 2019 The Bazel Authors. All rights reserved. |
| // |
| // 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. |
| |
| package com.google.devtools.build.lib.syntax; |
| |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkModule; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkValue; |
| |
| /** The type of the Starlark None value. */ |
| @SkylarkModule(name = "NoneType", documented = false, doc = "The type of the Starlark None value.") |
| @Immutable |
| public final class NoneType implements SkylarkValue { |
| |
| static final NoneType NONE = new NoneType(); |
| |
| private NoneType() {} |
| |
| @Override |
| public String toString() { |
| return "None"; |
| } |
| |
| @Override |
| public boolean isImmutable() { |
| return true; |
| } |
| |
| @Override |
| public boolean truth() { |
| return false; |
| } |
| |
| @Override |
| public void repr(SkylarkPrinter printer) { |
| printer.append("None"); |
| } |
| } |