Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.commons.jxpath.ri; /** * The Compiler APIs are completely agnostic to the actual types of objects * produced and consumed by the APIs. Arguments and return values are * declared as java.lang.Object. * <p> * Since objects returned by Compiler methods are passed as arguments to other * Compiler methods, the descriptions of these methods use virtual types. There * are four virtual object types: EXPRESSION, QNAME, STEP and NODE_TEST. * <p> * The following example illustrates this notion. This sequence compiles * the xpath "foo[round(1 div 2)]/text()": * <blockquote><pre> * Object qname1 = compiler.qname(null, "foo") * Object expr1 = compiler.number("1"); * Object expr2 = compiler.number("2"); * Object expr3 = compiler.div(expr1, expr2); * Object expr4 = compiler. * coreFunction(Compiler.FUNCTION_ROUND, new Object[]{expr3}); * Object test1 = compiler.nodeNameTest(qname1); * Object step1 = compiler. * step(Compiler.AXIS_CHILD, test1, new Object[]{expr4}); * Object test2 = compiler.nodeTypeTest(Compiler.NODE_TYPE_TEXT); * Object step2 = compiler.nodeTypeTest(Compiler.AXIS_CHILD, test2, null); * Object expr5 = compiler.locationPath(false, new Object[]{step1, step2}); * </pre></blockquote> * * @author Dmitri Plotnikov * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $ */ public interface Compiler { public static final int NODE_TYPE_NODE = 1; public static final int NODE_TYPE_TEXT = 2; public static final int NODE_TYPE_COMMENT = 3; public static final int NODE_TYPE_PI = 4; public static final int AXIS_SELF = 1; public static final int AXIS_CHILD = 2; public static final int AXIS_PARENT = 3; public static final int AXIS_ANCESTOR = 4; public static final int AXIS_ATTRIBUTE = 5; public static final int AXIS_NAMESPACE = 6; public static final int AXIS_PRECEDING = 7; public static final int AXIS_FOLLOWING = 8; public static final int AXIS_DESCENDANT = 9; public static final int AXIS_ANCESTOR_OR_SELF = 10; public static final int AXIS_FOLLOWING_SIBLING = 11; public static final int AXIS_PRECEDING_SIBLING = 12; public static final int AXIS_DESCENDANT_OR_SELF = 13; public static final int FUNCTION_LAST = 1; public static final int FUNCTION_POSITION = 2; public static final int FUNCTION_COUNT = 3; public static final int FUNCTION_ID = 4; public static final int FUNCTION_LOCAL_NAME = 5; public static final int FUNCTION_NAMESPACE_URI = 6; public static final int FUNCTION_NAME = 7; public static final int FUNCTION_STRING = 8; public static final int FUNCTION_CONCAT = 9; public static final int FUNCTION_STARTS_WITH = 10; public static final int FUNCTION_CONTAINS = 11; public static final int FUNCTION_SUBSTRING_BEFORE = 12; public static final int FUNCTION_SUBSTRING_AFTER = 13; public static final int FUNCTION_SUBSTRING = 14; public static final int FUNCTION_STRING_LENGTH = 15; public static final int FUNCTION_NORMALIZE_SPACE = 16; public static final int FUNCTION_TRANSLATE = 17; public static final int FUNCTION_BOOLEAN = 18; public static final int FUNCTION_NOT = 19; public static final int FUNCTION_TRUE = 20; public static final int FUNCTION_FALSE = 21; public static final int FUNCTION_LANG = 22; public static final int FUNCTION_NUMBER = 23; public static final int FUNCTION_SUM = 24; public static final int FUNCTION_FLOOR = 25; public static final int FUNCTION_CEILING = 26; public static final int FUNCTION_ROUND = 27; public static final int FUNCTION_NULL = 28; public static final int FUNCTION_KEY = 29; public static final int FUNCTION_FORMAT_NUMBER = 30; /** * Produces an EXPRESSION object that represents a numeric constant. * @param value numeric String * @return Object */ Object number(String value); /** * Produces an EXPRESSION object that represents a string constant. * @param value String literal * @return Object */ Object literal(String value); /** * Produces an QNAME that represents a name with an optional prefix. * @param prefix String prefix * @param name String name * @return Object */ Object qname(String prefix, String name); /** * Produces an EXPRESSION object representing the sum of all argumens * * @param arguments are EXPRESSION objects * @return Object */ Object sum(Object[] arguments); /** * Produces an EXPRESSION object representing <i>left</i> minus <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object minus(Object left, Object right); /** * Produces an EXPRESSION object representing <i>left</i> multiplied by * <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object multiply(Object left, Object right); /** * Produces an EXPRESSION object representing <i>left</i> divided by * <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object divide(Object left, Object right); /** * Produces an EXPRESSION object representing <i>left</i> modulo * <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object mod(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> less than <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object lessThan(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> less than or equal to <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object lessThanOrEqual(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> greater than <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object greaterThan(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> greater than or equal to <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object greaterThanOrEqual(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> equals to <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object equal(Object left, Object right); /** * Produces an EXPRESSION object representing the comparison: * <i>left</i> is not equal to <i>right</i> * * @param left is an EXPRESSION object * @param right is an EXPRESSION object * @return Object */ Object notEqual(Object left, Object right); /** * Produces an EXPRESSION object representing unary negation of the argument * * @param argument is an EXPRESSION object * @return Object */ Object minus(Object argument); /** * Produces an EXPRESSION object representing variable reference * * @param qname is a QNAME object * @return Object */ Object variableReference(Object qname); /** * Produces an EXPRESSION object representing the computation of * a core function with the supplied arguments. * * @param code is one of FUNCTION_... constants * @param args are EXPRESSION objects * @return Object */ Object function(int code, Object[] args); /** * Produces an EXPRESSION object representing the computation of * a library function with the supplied arguments. * * @param name is a QNAME object (function name) * @param args are EXPRESSION objects * @return Object */ Object function(Object name, Object[] args); /** * Produces an EXPRESSION object representing logical conjunction of * all arguments * * @param arguments are EXPRESSION objects * @return Object */ Object and(Object[] arguments); /** * Produces an EXPRESSION object representing logical disjunction of * all arguments * * @param arguments are EXPRESSION objects * @return Object */ Object or(Object[] arguments); /** * Produces an EXPRESSION object representing union of all node sets * * @param arguments are EXPRESSION objects * @return Object */ Object union(Object[] arguments); /** * Produces a NODE_TEST object that represents a node name test. * * @param qname is a QNAME object * @return Object */ Object nodeNameTest(Object qname); /** * Produces a NODE_TEST object that represents a node type test. * * @param nodeType is a NODE_TEST object * @return Object */ Object nodeTypeTest(int nodeType); /** * Produces a NODE_TEST object that represents a processing instruction * test. * * @param instruction is a NODE_TEST object * @return Object */ Object processingInstructionTest(String instruction); /** * Produces a STEP object that represents a node test. * * @param axis is one of the AXIS_... constants * @param nodeTest is a NODE_TEST object * @param predicates are EXPRESSION objects * @return Object */ Object step(int axis, Object nodeTest, Object[] predicates); /** * Produces an EXPRESSION object representing a location path * * @param absolute indicates whether the path is absolute * @param steps are STEP objects * @return Object */ Object locationPath(boolean absolute, Object[] steps); /** * Produces an EXPRESSION object representing a filter expression * * @param expression is an EXPRESSION object * @param predicates are EXPRESSION objects * @param steps are STEP objects * @return Object */ Object expressionPath(Object expression, Object[] predicates, Object[] steps); }