001/* 002 * Copyright (c) 2007-2015 Concurrent, Inc. All Rights Reserved. 003 * 004 * Project and contact information: http://www.cascading.org/ 005 * 006 * This file is part of the Cascading project. 007 * 008 * Licensed under the Apache License, Version 2.0 (the "License"); 009 * you may not use this file except in compliance with the License. 010 * You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, software 015 * distributed under the License is distributed on an "AS IS" BASIS, 016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 017 * See the License for the specific language governing permissions and 018 * limitations under the License. 019 */ 020 021package cascading.flow.planner.iso.expression; 022 023import cascading.flow.planner.Scope; 024 025/** 026 * If ScopeExpression is the only edge, the {@link ScopeExpression.Applies} enum will apply, 027 * otherwise the number of edges on the target graph must match the number of edges in the expression. 028 */ 029public abstract class ScopeExpression implements Expression<Scope> 030 { 031 /** 032 * Where this expression applies between ANY edge between two nodes. 033 */ 034 public static final PathScopeExpression ANY = new PathScopeExpression( Applies.Any ); 035 /** 036 * Where this expression applies between ALL edges between two nodes. 037 */ 038 public static final PathScopeExpression ALL = new PathScopeExpression( Applies.All ); 039 public static final PathScopeExpression EACH = new PathScopeExpression( Applies.Each ); // unsupported 040 041 public enum Applies 042 { 043 Any, All, Each 044 } 045 046 protected Applies applies = Applies.Any; 047 048 protected ScopeExpression() 049 { 050 } 051 052 protected ScopeExpression( Applies applies ) 053 { 054 this.applies = applies; 055 } 056 057 public boolean appliesToAllPaths() 058 { 059 return applies == Applies.All; 060 } 061 062 public boolean appliesToAnyPath() 063 { 064 return applies == Applies.Any; 065 } 066 067 public boolean appliesToEachPath() 068 { 069 return applies == Applies.Each; 070 } 071 072 public boolean acceptsAll() 073 { 074 return appliesToAllPaths(); 075 } 076 077 public Applies getApplies() 078 { 079 return applies; 080 } 081 }