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: BoolStack.java 468655 2006-10-28 07:12:06Z minchau $ 209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpackage org.apache.xml.utils; 229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/** 259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Simple stack for boolean values. 269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @xsl.usage internal 279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpublic final class BoolStack implements Cloneable 299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson{ 309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** Array of boolean values */ 329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private boolean m_values[]; 339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** Array size allocated */ 359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private int m_allocatedSize; 369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** Index into the array of booleans */ 389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private int m_index; 399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Default constructor. Note that the default 429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * block size is very small, for small lists. 439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public BoolStack() 459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson this(32); 479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Construct a IntVector, using the given block size. 519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param size array size to allocate 539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public BoolStack(int size) 559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_allocatedSize = size; 589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_values = new boolean[size]; 599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_index = -1; 609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Get the length of the list. 649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return Current length of the list 669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final int size() 689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return m_index + 1; 709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Clears the stack. 749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final void clear() 779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_index = -1; 799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Pushes an item onto the top of this stack. 839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param val the boolean to be pushed onto this stack. 869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return the <code>item</code> argument. 879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean push(boolean val) 899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson if (m_index == m_allocatedSize - 1) 929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson grow(); 939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return (m_values[++m_index] = val); 959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Removes the object at the top of this stack and returns that 999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * object as the value of this function. 1009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return The object at the top of this stack. 1029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws EmptyStackException if this stack is empty. 1039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean pop() 1059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return m_values[m_index--]; 1079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Removes the object at the top of this stack and returns the 1119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * next object at the top as the value of this function. 1129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return Next object to the top or false if none there 1159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean popAndTop() 1179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_index--; 1209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return (m_index >= 0) ? m_values[m_index] : false; 1229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Set the item at the top of this stack 1269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param b Object to set at the top of this stack 1299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final void setTop(boolean b) 1319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_values[m_index] = b; 1339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Looks at the object at the top of this stack without removing it 1379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * from the stack. 1389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return the object at the top of this stack. 1409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws EmptyStackException if this stack is empty. 1419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean peek() 1439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return m_values[m_index]; 1459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Looks at the object at the top of this stack without removing it 1499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * from the stack. If the stack is empty, it returns false. 1509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return the object at the top of this stack. 1529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean peekOrFalse() 1549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return (m_index > -1) ? m_values[m_index] : false; 1569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Looks at the object at the top of this stack without removing it 1609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * from the stack. If the stack is empty, it returns true. 1619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return the object at the top of this stack. 1639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public final boolean peekOrTrue() 1659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return (m_index > -1) ? m_values[m_index] : true; 1679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Tests if this stack is empty. 1719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return <code>true</code> if this stack is empty; 1739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * <code>false</code> otherwise. 1749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public boolean isEmpty() 1769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return (m_index == -1); 1789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Grows the size of the stack 1829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson private void grow() 1859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_allocatedSize *= 2; 1889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson boolean newVector[] = new boolean[m_allocatedSize]; 1909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson System.arraycopy(m_values, 0, newVector, 0, m_index + 1); 1929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson m_values = newVector; 1949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public Object clone() 1979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws CloneNotSupportedException 1989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return super.clone(); 2009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 2019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson} 203