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Java > Open Source Codes > org > eclipse > jdt > internal > compiler > ast > DoubleLiteral


1 /*******************************************************************************
2  * Copyright (c) 2000, 2006 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  * IBM Corporation - initial API and implementation
10  *******************************************************************************/
11 package org.eclipse.jdt.internal.compiler.ast;
12
13 import org.eclipse.jdt.internal.compiler.ASTVisitor;
14 import org.eclipse.jdt.internal.compiler.impl.*;
15 import org.eclipse.jdt.internal.compiler.codegen.*;
16 import org.eclipse.jdt.internal.compiler.lookup.*;
17 import org.eclipse.jdt.internal.compiler.util.FloatUtil;
18
19 public class DoubleLiteral extends NumberLiteral {
20     double value;
21     public DoubleLiteral(char[] token, int s, int e) {
22         super(token, s, e);
23     }
24     public void computeConstant() {
25         Double JavaDoc computedValue;
26         try {
27             computedValue = Double.valueOf(String.valueOf(source));
28         } catch (NumberFormatException JavaDoc e) {
29             // hex floating point literal
30 // being rejected by 1.4 libraries where Double.valueOf(...) doesn't handle hex decimal floats
31 try {
32                 double v = FloatUtil.valueOfHexDoubleLiteral(source);
33                 if (v == Double.POSITIVE_INFINITY) {
34                     // error: the number is too large to represent
35 return;
36                 }
37                 if (Double.isNaN(v)) {
38                     // error: the number is too small to represent
39 return;
40                 }
41                 value = v;
42                 constant = DoubleConstant.fromValue(v);
43             } catch (NumberFormatException JavaDoc e1) {
44                 // if the computation of the constant fails
45 }
46             return;
47         }
48
49         final double doubleValue = computedValue.doubleValue();
50         if (doubleValue > Double.MAX_VALUE) {
51             // error: the number is too large to represent
52 return;
53         }
54         if (doubleValue < Double.MIN_VALUE) {
55             // see 1F6IGUU
56 // a true 0 only has '0' and '.' in mantissa
57 // 1.0e-5000d is non-zero, but underflows to 0
58 boolean isHexaDecimal = false;
59             label : for (int i = 0; i < source.length; i++) { //it is welled formated so just test against '0' and potential . D d
60 switch (source[i]) {
61                     case '0' :
62                     case '.' :
63                         break;
64                     case 'x' :
65                     case 'X' :
66                         isHexaDecimal = true;
67                         break;
68                     case 'e' :
69                     case 'E' :
70                     case 'f' :
71                     case 'F' :
72                     case 'd' :
73                     case 'D' :
74                         if (isHexaDecimal) {
75                             return;
76                         }
77                         // starting the exponent - mantissa is all zero
78 // no exponent - mantissa is all zero
79 break label;
80                     case 'p' :
81                     case 'P' :
82                         break label;
83                     default :
84                         // error: the number is too small to represent
85 return;
86                 }
87             }
88         }
89         value = doubleValue;
90         constant = DoubleConstant.fromValue(value);
91     }
92     /**
93      * Code generation for the double literak
94      *
95      * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
96      * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
97      * @param valueRequired boolean
98      */
99     public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
100         int pc = codeStream.position;
101         if (valueRequired) {
102             codeStream.generateConstant(constant, implicitConversion);
103         }
104         codeStream.recordPositionsFrom(pc, this.sourceStart);
105     }
106     public TypeBinding literalType(BlockScope scope) {
107         return TypeBinding.DOUBLE;
108     }
109     public void traverse(ASTVisitor visitor, BlockScope scope) {
110         visitor.visit(this, scope);
111         visitor.endVisit(this, scope);
112     }
113 }
114
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