19f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 29f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Licensed to the Apache Software Foundation (ASF) under one 39f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * or more contributor license agreements. See the NOTICE file 49f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed with this work for additional information 59f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * regarding copyright ownership. The ASF licenses this file 69f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * to you under the Apache License, Version 2.0 (the "License"); 79f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * you may not use this file except in compliance with the License. 89f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * You may obtain a copy of the License at 99f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * http://www.apache.org/licenses/LICENSE-2.0 119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Unless required by applicable law or agreed to in writing, software 139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed under the License is distributed on an "AS IS" BASIS, 149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * See the License for the specific language governing permissions and 169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * limitations under the License. 179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * $Id: HasPositionalPredChecker.java 468655 2006-10-28 07:12:06Z minchau $ 209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpackage org.apache.xpath.axes; 229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.Expression; 249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.ExpressionOwner; 259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.XPathVisitor; 269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.functions.FuncLast; 279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.functions.FuncPosition; 289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.functions.Function; 299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.objects.XNumber; 309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Div; 319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Minus; 329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Mod; 339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Mult; 349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Plus; 359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Quo; 369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.operations.Variable; 379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpublic class HasPositionalPredChecker extends XPathVisitor 399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson{ 409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private boolean m_hasPositionalPred = false; 419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private int m_predDepth = 0; 429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Process the LocPathIterator to see if it contains variables 459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * or functions that may make it context dependent. 469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param path LocPathIterator that is assumed to be absolute, but needs checking. 479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return true if the path is confirmed to be absolute, false if it 489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * may contain context dependencies. 499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static boolean check(LocPathIterator path) 519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson HasPositionalPredChecker hppc = new HasPositionalPredChecker(); 539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson path.callVisitors(null, hppc); 549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return hppc.m_hasPositionalPred; 559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Visit a function. 599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param owner The owner of the expression, to which the expression can 609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * be reset if rewriting takes place. 619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param func The function reference object. 629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return true if the sub expressions should be traversed. 639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public boolean visitFunction(ExpressionOwner owner, Function func) 659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if((func instanceof FuncPosition) || 679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (func instanceof FuncLast)) 689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_hasPositionalPred = true; 699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return true; 709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// /** 739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// * Visit a variable reference. 749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// * @param owner The owner of the expression, to which the expression can 759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// * be reset if rewriting takes place. 769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// * @param var The variable reference object. 779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// * @return true if the sub expressions should be traversed. 789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// */ 799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// public boolean visitVariableRef(ExpressionOwner owner, Variable var) 809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// { 819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// m_hasPositionalPred = true; 829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// return true; 839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson// } 849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Visit a predicate within a location path. Note that there isn't a 879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * proper unique component for predicates, and that the expression will 889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * be called also for whatever type Expression is. 899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param owner The owner of the expression, to which the expression can 919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * be reset if rewriting takes place. 929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param pred The predicate object. 939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return true if the sub expressions should be traversed. 949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public boolean visitPredicate(ExpressionOwner owner, Expression pred) 969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_predDepth++; 989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if(m_predDepth == 1) 1009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if((pred instanceof Variable) || 1029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof XNumber) || 1039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Div) || 1049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Plus) || 1059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Minus) || 1069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Mod) || 1079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Quo) || 1089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Mult) || 1099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof org.apache.xpath.operations.Number) || 1109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (pred instanceof Function)) 1119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_hasPositionalPred = true; 1129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson else 1139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson pred.callVisitors(owner, this); 1149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_predDepth--; 1179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Don't go have the caller go any further down the subtree. 1199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return false; 1209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson} 1249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 125