Unifiable.java

/*
 * Copyright 2013 Google Inc. 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.errorprone.refaster;

import java.io.Serializable;

import javax.annotation.Nullable;

/**
 * A serializable representation of a template that can be matched against a target of type
 * {@code T}.
 *
 * @author Louis Wasserman
 */
public interface Unifiable<T> extends Serializable {
  /**
   * Attempt to unify this template against the specified target, tracking progress (such as
   * variable bindings) with the specified {@code Unifier}.
   *
   * @return a Unifier derived from {@code unifier} if the match was successful, containing all
   *         metadata about the match, or {@code null} if the match was unsuccessful or
   *         {@code unifier} was null.
   */
  @Nullable
  Unifier unify(T target, @Nullable Unifier unifier);
}