/*
* Copyright 2009 Google Inc.
*
* 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.gwt.dev.jjs.impl.gflow;
/**
* Assumptions are members of the lattice used in the analysis. Assumptions
* are associated with graph edges and depict analysis knowledge about the flow.
*
* So far we need only join operation to perform analysis.
*
* Lattice's bottom should be represented by <code>null</null>.
*
* Assumption should implement correct equals() and hashCode() methods.
*
* @param <Self> self type.
*/
public interface Assumption<Self extends Assumption<?>> {
/**
* Compute least upper bound. Should accept <code>null</null>.
* It's allowed to return value, equal either to <code>this</code> or to
* <code>other</code>. If you're going to modify result of join operation,
* you have to copy it.
*/
Self join(Self other);
}