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1
52
53 package freemarker.core;
54
55 import java.util.Date  ;
56 import freemarker.template.*;
57
58
63
64 final class ComparisonExpression extends BooleanExpression {
65
66 static final int EQUALS=1;
67 static final int NOT_EQUALS=2;
68 static final int LESS_THAN=3;
69 static final int GREATER_THAN=4;
70 static final int LESS_THAN_EQUALS=5;
71 static final int GREATER_THAN_EQUALS=6;
72
73 private final Expression left;
74 private final Expression right;
75 private final int operation;
76 private final String opString;
77
78 ComparisonExpression(Expression left, Expression right, String opString) {
79 this.left = left;
80 this.right = right;
81 opString = opString.intern();
82 this.opString = opString;
83 if (opString == "==" || opString == "=") {
84 operation = EQUALS;
85 }
86 else if (opString == "!=") {
87 operation = NOT_EQUALS;
88 }
89 else if (opString == "gt" || opString == "\\gt" || opString == ">" || opString == ">") {
90 operation = GREATER_THAN;
91 }
92 else if (opString == "gte" || opString == "\\gte" || opString == ">=" || opString == ">=") {
93 operation = GREATER_THAN_EQUALS;
94 }
95 else if (opString== "lt" || opString == "\\lt" || opString == "<" || opString == "<") {
96 operation = LESS_THAN;
97 }
98 else if (opString == "lte" || opString == "\\lte" || opString == "<=" || opString == "<=") {
99 operation = LESS_THAN_EQUALS;
100 }
101 else {
102 throw new RuntimeException ("Unknown comparison operator " + opString);
103 }
104 }
105
106
110 boolean isTrue(Environment env) throws TemplateException {
111 TemplateModel ltm = left.getAsTemplateModel(env);
112 TemplateModel rtm = right.getAsTemplateModel(env);
113 if (env != null && env.isClassicCompatible()) {
114 if (ltm == null) {
115 ltm = TemplateScalarModel.EMPTY_STRING;
116 }
117 if (rtm == null) {
118 rtm = TemplateScalarModel.EMPTY_STRING;
119 }
120 }
121 assertNonNull(ltm, left, env);
122 assertNonNull(rtm, right, env);
123 int comp = 0;
124 if(ltm instanceof TemplateNumberModel && rtm instanceof TemplateNumberModel) {
125 Number first = EvaluationUtil.getNumber((TemplateNumberModel)ltm, left, env);
126 Number second = EvaluationUtil.getNumber((TemplateNumberModel)rtm, right, env);
127 ArithmeticEngine ae =
128 env != null
129 ? env.getArithmeticEngine()
130 : getTemplate().getArithmeticEngine();
131 comp = ae.compareNumbers(first, second);
132 }
133 else if(ltm instanceof TemplateDateModel && rtm instanceof TemplateDateModel) {
134 TemplateDateModel ltdm = (TemplateDateModel)ltm;
135 TemplateDateModel rtdm = (TemplateDateModel)rtm;
136 int ltype = ltdm.getDateType();
137 int rtype = rtdm.getDateType();
138 if(ltype != rtype) {
139 throw new TemplateException(
140 "Can not compare dates of different type. Left date is of "
141 + TemplateDateModel.TYPE_NAMES.get(ltype)
142 + " type, right date is of "
143 + TemplateDateModel.TYPE_NAMES.get(rtype) + " type.",
144 env);
145 }
146 if(ltype == TemplateDateModel.UNKNOWN) {
147 throw new TemplateException(
148 "Left date is of UNKNOWN type, and can not be compared.", env);
149 }
150 if(rtype == TemplateDateModel.UNKNOWN) {
151 throw new TemplateException(
152 "Right date is of UNKNOWN type, and can not be compared.", env);
153 }
154
155 Date first = EvaluationUtil.getDate(ltdm, left, env);
156 Date second = EvaluationUtil.getDate(rtdm, right, env);
157 comp = first.compareTo(second);
158 }
159 else if(ltm instanceof TemplateScalarModel && rtm instanceof TemplateScalarModel) {
160 if(operation != EQUALS && operation != NOT_EQUALS) {
161 throw new TemplateException("Can not use operator " + opString + " on string values.", env);
162 }
163 String first = EvaluationUtil.getString((TemplateScalarModel)ltm, left, env);
164 String second = EvaluationUtil.getString((TemplateScalarModel)rtm, right, env);
165 comp = env.getCollator().compare(first, second);
166 }
167 else if(ltm instanceof TemplateBooleanModel && rtm instanceof TemplateBooleanModel) {
168 if(operation != EQUALS && operation != NOT_EQUALS) {
169 throw new TemplateException("Can not use operator " + opString + " on boolean values.", env);
170 }
171 boolean first = ((TemplateBooleanModel)ltm).getAsBoolean();
172 boolean second = ((TemplateBooleanModel)rtm).getAsBoolean();
173 comp = (first ? 1 : 0) - (second ? 1 : 0);
174 }
175 else if(env.isClassicCompatible()) {
177 String first = left.getStringValue(env);
178 String second = right.getStringValue(env);
179 comp = env.getCollator().compare(first, second);
180 }
181 else {
182 throw new TemplateException(
183 "The only legal comparisons are between two numbers, two strings, or two dates.\n"
184 + "Left hand operand is a " + ltm.getClass().getName() + "\n"
185 + "Right hand operand is a " + rtm.getClass().getName() + "\n"
186 , env);
187 }
188 switch (operation) {
189 case EQUALS:
190 return comp == 0;
191 case NOT_EQUALS:
192 return comp != 0;
193 case LESS_THAN :
194 return comp < 0;
195 case GREATER_THAN :
196 return comp > 0;
197 case LESS_THAN_EQUALS :
198 return comp <= 0;
199 case GREATER_THAN_EQUALS :
200 return comp >= 0;
201 default :
202 throw new TemplateException("unknown operation", env);
203 }
204 }
205
206 public String getCanonicalForm() {
207 return left.getCanonicalForm() + ' ' + opString + ' ' + right.getCanonicalForm();
208 }
209
210 boolean isLiteral() {
211 return constantValue != null || (left.isLiteral() && right.isLiteral());
212 }
213
214 Expression _deepClone(String name, Expression subst) {
215 return new ComparisonExpression(left.deepClone(name, subst), right.deepClone(name, subst), opString);
216 }
217 }
218 |
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