001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.language.simple.ast;
018
019 import org.apache.camel.CamelExchangeException;
020 import org.apache.camel.Exchange;
021 import org.apache.camel.Expression;
022 import org.apache.camel.NoTypeConversionAvailableException;
023 import org.apache.camel.language.simple.types.SimpleParserException;
024 import org.apache.camel.language.simple.types.SimpleToken;
025 import org.apache.camel.language.simple.types.UnaryOperatorType;
026 import org.apache.camel.util.ObjectHelper;
027
028 /**
029 * Represents an unary expression in the AST
030 */
031 public class UnaryExpression extends BaseSimpleNode {
032
033 private UnaryOperatorType operator;
034 private SimpleNode left;
035
036 public UnaryExpression(SimpleToken token) {
037 super(token);
038 operator = UnaryOperatorType.asOperator(token.getText());
039 }
040
041 @Override
042 public String toString() {
043 if (left != null) {
044 return left + token.getText();
045 } else {
046 return token.getText();
047 }
048 }
049
050 /**
051 * Accepts the left node to this operator
052 *
053 * @param left the left node to accept
054 */
055 public void acceptLeft(SimpleNode left) {
056 this.left = left;
057 }
058
059 public UnaryOperatorType getOperator() {
060 return operator;
061 }
062
063 @Override
064 public Expression createExpression(String expression) {
065 ObjectHelper.notNull(left, "left node", this);
066
067 final Expression leftExp = left.createExpression(expression);
068
069 if (operator == UnaryOperatorType.INC) {
070 return createIncExpression(leftExp);
071 } else if (operator == UnaryOperatorType.DEC) {
072 return createDecExpression(leftExp);
073 }
074
075 throw new SimpleParserException("Unknown unary operator " + operator, token.getIndex());
076 }
077
078 private Expression createIncExpression(final Expression leftExp) {
079 return new Expression() {
080 @Override
081 public <T> T evaluate(Exchange exchange, Class<T> type) {
082 Number num = leftExp.evaluate(exchange, Number.class);
083 if (num != null) {
084 long val = num.longValue();
085 val++;
086
087 // convert value back to same type as input as we want to preserve type
088 Object left = leftExp.evaluate(exchange, Object.class);
089 try {
090 left = exchange.getContext().getTypeConverter().mandatoryConvertTo(left.getClass(), exchange, val);
091 } catch (NoTypeConversionAvailableException e) {
092 throw ObjectHelper.wrapRuntimeCamelException(e);
093 }
094
095 // and return the result
096 return exchange.getContext().getTypeConverter().convertTo(type, left);
097 }
098 // cannot convert the expression as a number
099 Exception cause = new CamelExchangeException("Cannot evaluate " + leftExp + " as a number", exchange);
100 throw ObjectHelper.wrapRuntimeCamelException(cause);
101 }
102
103 @Override
104 public String toString() {
105 return left + operator.toString();
106 }
107 };
108 }
109
110 private Expression createDecExpression(final Expression leftExp) {
111 return new Expression() {
112 @Override
113 public <T> T evaluate(Exchange exchange, Class<T> type) {
114 Number num = leftExp.evaluate(exchange, Number.class);
115 if (num != null) {
116 long val = num.longValue();
117 val--;
118
119 // convert value back to same type as input as we want to preserve type
120 Object left = leftExp.evaluate(exchange, Object.class);
121 try {
122 left = exchange.getContext().getTypeConverter().mandatoryConvertTo(left.getClass(), exchange, val);
123 } catch (NoTypeConversionAvailableException e) {
124 throw ObjectHelper.wrapRuntimeCamelException(e);
125 }
126
127 // and return the result
128 return exchange.getContext().getTypeConverter().convertTo(type, left);
129 }
130 // cannot convert the expression as a number
131 Exception cause = new CamelExchangeException("Cannot evaluate " + leftExp + " as a number", exchange);
132 throw ObjectHelper.wrapRuntimeCamelException(cause);
133 }
134
135 @Override
136 public String toString() {
137 return left + operator.toString();
138 }
139 };
140 }
141
142 }