| // Copyright 2016 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.events.Location; |
| import com.google.devtools.build.lib.syntax.Mutability.Freezable; |
| import com.google.devtools.build.lib.syntax.Mutability.MutabilityException; |
| |
| /** |
| * Marker interface for indicating a freezable Starlark value whose mutation operations check a |
| * {@link Mutability}. |
| */ |
| // TODO(adonovan): merge with Freezable once StarlarkThread and Frame no longer implement Freezable. |
| public interface StarlarkMutable extends Freezable, StarlarkValue { |
| |
| /** |
| * Throws an exception if this object is not mutable. |
| * |
| * <p>This method is essentially a mix-in. Subclasses should not override it. |
| * |
| * @throws EvalException if the object is not mutable. This may be because the {@code |
| * this.mutability()} is frozen, or because it is temporarily locked by an active loop |
| * iteration. |
| */ |
| default void checkMutable(Location loc) throws EvalException { |
| try { |
| Mutability.checkMutable(this, mutability()); |
| } catch (MutabilityException ex) { |
| throw new EvalException(loc, ex); |
| } |
| } |
| } |