001: /*
002: * Copyright (c) 2003 The Visigoth Software Society. All rights
003: * reserved.
004: *
005: * Redistribution and use in source and binary forms, with or without
006: * modification, are permitted provided that the following conditions
007: * are met:
008: *
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: *
012: * 2. Redistributions in binary form must reproduce the above copyright
013: * notice, this list of conditions and the following disclaimer in
014: * the documentation and/or other materials provided with the
015: * distribution.
016: *
017: * 3. The end-user documentation included with the redistribution, if
018: * any, must include the following acknowledgement:
019: * "This product includes software developed by the
020: * Visigoth Software Society (http://www.visigoths.org/)."
021: * Alternately, this acknowledgement may appear in the software itself,
022: * if and wherever such third-party acknowledgements normally appear.
023: *
024: * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
025: * project contributors may be used to endorse or promote products derived
026: * from this software without prior written permission. For written
027: * permission, please contact visigoths@visigoths.org.
028: *
029: * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
030: * nor may "FreeMarker" or "Visigoth" appear in their names
031: * without prior written permission of the Visigoth Software Society.
032: *
033: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
034: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
035: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
036: * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
037: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
038: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
039: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
040: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
041: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
042: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
043: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
044: * SUCH DAMAGE.
045: * ====================================================================
046: *
047: * This software consists of voluntary contributions made by many
048: * individuals on behalf of the Visigoth Software Society. For more
049: * information on the Visigoth Software Society, please see
050: * http://www.visigoths.org/
051: */
052:
053: package freemarker.core;
054:
055: import freemarker.template.*;
056:
057: /**
058: * An operator for arithmetic operations. Note that the + operator
059: * also does string concatenation for backward compatibility.
060: * @author <a href="mailto:jon@revusky.com">Jonathan Revusky</a>
061: */
062: final class ArithmeticExpression extends Expression {
063:
064: static final int SUBSTRACTION = 0;
065: static final int MULTIPLICATION = 1;
066: static final int DIVISION = 2;
067: static final int MODULUS = 3;
068:
069: private static final char[] OPERATORS = new char[] { '-', '*', '/',
070: '%' };
071:
072: private final Expression left;
073: private final Expression right;
074: private final int operation;
075:
076: ArithmeticExpression(Expression left, Expression right,
077: int operation) {
078: this .left = left;
079: this .right = right;
080: this .operation = operation;
081: }
082:
083: TemplateModel _getAsTemplateModel(Environment env)
084: throws TemplateException {
085: TemplateModel leftModel = left.getAsTemplateModel(env);
086: TemplateModel rightModel = right.getAsTemplateModel(env);
087: boolean leftIsNumber = (leftModel instanceof TemplateNumberModel);
088: boolean rightIsNumber = (rightModel instanceof TemplateNumberModel);
089: boolean bothNumbers = leftIsNumber && rightIsNumber;
090: if (!bothNumbers) {
091: String msg = "Error " + getStartLocation();
092: if (!leftIsNumber) {
093: msg += "\nExpression " + left + " is not numerical";
094: }
095: if (!rightIsNumber) {
096: msg += "\nExpression " + right + " is not numerical";
097: }
098: throw new NonNumericalException(msg, env);
099: }
100: Number first = EvaluationUtil.getNumber(leftModel, left, env);
101: Number second = EvaluationUtil
102: .getNumber(rightModel, right, env);
103: ArithmeticEngine ae = env != null ? env.getArithmeticEngine()
104: : getTemplate().getArithmeticEngine();
105: switch (operation) {
106: case SUBSTRACTION:
107: return new SimpleNumber(ae.subtract(first, second));
108: case MULTIPLICATION:
109: return new SimpleNumber(ae.multiply(first, second));
110: case DIVISION:
111: return new SimpleNumber(ae.divide(first, second));
112: case MODULUS:
113: return new SimpleNumber(ae.modulus(first, second));
114: default:
115: throw new TemplateException("unknown operation : "
116: + operation, env);
117: }
118: }
119:
120: public String getCanonicalForm() {
121: return left.getCanonicalForm() + ' ' + OPERATORS[operation]
122: + ' ' + right.getCanonicalForm();
123: }
124:
125: boolean isLiteral() {
126: return constantValue != null
127: || (left.isLiteral() && right.isLiteral());
128: }
129:
130: Expression _deepClone(String name, Expression subst) {
131: return new ArithmeticExpression(left.deepClone(name, subst),
132: right.deepClone(name, subst), operation);
133: }
134: }
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