001: /*
002: * Copyright (c) 2005 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: final class UnaryPlusMinusExpression extends Expression {
058:
059: private final Expression target;
060: private final boolean isMinus;
061: private static final Integer MINUS_ONE = new Integer(-1);
062:
063: UnaryPlusMinusExpression(Expression target, boolean isMinus) {
064: this .target = target;
065: this .isMinus = isMinus;
066: }
067:
068: TemplateModel _getAsTemplateModel(Environment env)
069: throws TemplateException {
070: TemplateNumberModel targetModel = null;
071: try {
072: targetModel = (TemplateNumberModel) target
073: .getAsTemplateModel(env);
074: } catch (ClassCastException cce) {
075: String msg = "Error " + getStartLocation();
076: msg += "\nExpression " + target + " is not numerical.";
077: throw new NonNumericalException(msg, env);
078: }
079: if (!isMinus) {
080: return targetModel;
081: }
082: Number n = targetModel.getAsNumber();
083: n = ArithmeticEngine.CONSERVATIVE_ENGINE.multiply(MINUS_ONE, n);
084: return new SimpleNumber(n);
085: }
086:
087: public String getCanonicalForm() {
088: String op = isMinus ? "-" : "+";
089: return op + target.getCanonicalForm();
090: }
091:
092: boolean isLiteral() {
093: return target.isLiteral();
094: }
095:
096: Expression _deepClone(String name, Expression subst) {
097: return new UnaryPlusMinusExpression(target.deepClone(name,
098: subst), isMinus);
099: }
100: }
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