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CookCC - a Lexer / Parser (LALR(1)) Project
/*
* Copyright (c) 2003 The Visigoth Software Society. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.core;
import java.util.Date;
import freemarker.template.*;
/**
* A class that handles comparisons.
* @author Jonathan Revusky
* @author Attila Szegedi
*/
final class ComparisonExpression extends BooleanExpression {
static final int EQUALS=1;
static final int NOT_EQUALS=2;
static final int LESS_THAN=3;
static final int GREATER_THAN=4;
static final int LESS_THAN_EQUALS=5;
static final int GREATER_THAN_EQUALS=6;
private final Expression left;
private final Expression right;
private final int operation;
private final String opString;
ComparisonExpression(Expression left, Expression right, String opString) {
this.left = left;
this.right = right;
opString = opString.intern();
this.opString = opString;
if (opString == "==" || opString == "=") {
operation = EQUALS;
}
else if (opString == "!=") {
operation = NOT_EQUALS;
}
else if (opString == "gt" || opString == "\\gt" || opString == ">" || opString == ">") {
operation = GREATER_THAN;
}
else if (opString == "gte" || opString == "\\gte" || opString == ">=" || opString == ">=") {
operation = GREATER_THAN_EQUALS;
}
else if (opString== "lt" || opString == "\\lt" || opString == "<" || opString == "<") {
operation = LESS_THAN;
}
else if (opString == "lte" || opString == "\\lte" || opString == "<=" || opString == "<=") {
operation = LESS_THAN_EQUALS;
}
else {
throw new RuntimeException("Unknown comparison operator " + opString);
}
}
/*
* WARNING! This algorithm is duplicated in SequenceBuiltins.modelsEqual.
* Thus, if you update this method, then you have to update that too!
*/
boolean isTrue(Environment env) throws TemplateException {
TemplateModel ltm = left.getAsTemplateModel(env);
TemplateModel rtm = right.getAsTemplateModel(env);
if (env != null && env.isClassicCompatible()) {
if (ltm == null) {
ltm = TemplateScalarModel.EMPTY_STRING;
}
if (rtm == null) {
rtm = TemplateScalarModel.EMPTY_STRING;
}
}
assertNonNull(ltm, left, env);
assertNonNull(rtm, right, env);
int comp = 0;
if(ltm instanceof TemplateNumberModel && rtm instanceof TemplateNumberModel) {
Number first = EvaluationUtil.getNumber((TemplateNumberModel)ltm, left, env);
Number second = EvaluationUtil.getNumber((TemplateNumberModel)rtm, right, env);
ArithmeticEngine ae =
env != null
? env.getArithmeticEngine()
: getTemplate().getArithmeticEngine();
comp = ae.compareNumbers(first, second);
}
else if(ltm instanceof TemplateDateModel && rtm instanceof TemplateDateModel) {
TemplateDateModel ltdm = (TemplateDateModel)ltm;
TemplateDateModel rtdm = (TemplateDateModel)rtm;
int ltype = ltdm.getDateType();
int rtype = rtdm.getDateType();
if(ltype != rtype) {
throw new TemplateException(
"Can not compare dates of different type. Left date is of "
+ TemplateDateModel.TYPE_NAMES.get(ltype)
+ " type, right date is of "
+ TemplateDateModel.TYPE_NAMES.get(rtype) + " type.",
env);
}
if(ltype == TemplateDateModel.UNKNOWN) {
throw new TemplateException(
"Left date is of UNKNOWN type, and can not be compared.", env);
}
if(rtype == TemplateDateModel.UNKNOWN) {
throw new TemplateException(
"Right date is of UNKNOWN type, and can not be compared.", env);
}
Date first = EvaluationUtil.getDate(ltdm, left, env);
Date second = EvaluationUtil.getDate(rtdm, right, env);
comp = first.compareTo(second);
}
else if(ltm instanceof TemplateScalarModel && rtm instanceof TemplateScalarModel) {
if(operation != EQUALS && operation != NOT_EQUALS) {
throw new TemplateException("Can not use operator " + opString + " on string values.", env);
}
String first = EvaluationUtil.getString((TemplateScalarModel)ltm, left, env);
String second = EvaluationUtil.getString((TemplateScalarModel)rtm, right, env);
comp = env.getCollator().compare(first, second);
}
else if(ltm instanceof TemplateBooleanModel && rtm instanceof TemplateBooleanModel) {
if(operation != EQUALS && operation != NOT_EQUALS) {
throw new TemplateException("Can not use operator " + opString + " on boolean values.", env);
}
boolean first = ((TemplateBooleanModel)ltm).getAsBoolean();
boolean second = ((TemplateBooleanModel)rtm).getAsBoolean();
comp = (first ? 1 : 0) - (second ? 1 : 0);
}
// Here we handle compatibility issues
else if(env.isClassicCompatible()) {
String first = left.getStringValue(env);
String second = right.getStringValue(env);
comp = env.getCollator().compare(first, second);
}
else {
throw new TemplateException(
"The only legal comparisons are between two numbers, two strings, or two dates.\n"
+ "Left hand operand is a " + ltm.getClass().getName() + "\n"
+ "Right hand operand is a " + rtm.getClass().getName() + "\n"
, env);
}
switch (operation) {
case EQUALS:
return comp == 0;
case NOT_EQUALS:
return comp != 0;
case LESS_THAN :
return comp < 0;
case GREATER_THAN :
return comp > 0;
case LESS_THAN_EQUALS :
return comp <= 0;
case GREATER_THAN_EQUALS :
return comp >= 0;
default :
throw new TemplateException("unknown operation", env);
}
}
public String getCanonicalForm() {
return left.getCanonicalForm() + ' ' + opString + ' ' + right.getCanonicalForm();
}
boolean isLiteral() {
return constantValue != null || (left.isLiteral() && right.isLiteral());
}
Expression _deepClone(String name, Expression subst) {
return new ComparisonExpression(left.deepClone(name, subst), right.deepClone(name, subst), opString);
}
}