src/org/eclipse/jdt/internal/compiler/ast/FloatLiteral.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-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
  18 public class FloatLiteral extends NumberLiteral {
  19         float value;
  20         final static float Float_MIN_VALUE = Float.intBitsToFloat(1); // work-around VAJ problem 1F6IGUU
  21 public FloatLiteral(char[] token, int s, int e) {
  22         super(token, s,e);
  23 }
  24 public void computeConstant() {
  25
  26         //the source is correctly formated so the exception should never occurs
  27
  28         Float computedValue;
  29         try {
  30                 computedValue = Float.valueOf(String.valueOf(source));
  31         } catch (NumberFormatException e) {
  32                 return;
  33         }
  34
  35         if (computedValue.doubleValue() > Float.MAX_VALUE){
  36                 return; //may be Infinity
  37         }
  38         if (computedValue.floatValue() < Float_MIN_VALUE){
  39                 // see 1F6IGUU
  40                 //only a true 0 can be made of zeros
  41                 //1.00000000e-46f is illegal ....
  42                 label : for (int i = 0; i < source.length; i++) {
  43                         switch (source[i]) {
  44                                 case '.' :
  45                                 case 'f' :
  46                                 case 'F' :
  47                                 case '0' :
  48                                         break;
  49                                 case 'e' :
  50                                 case 'E' :
  51                                         break label; //exposant are valid !....
  52                                 default :
  53                                         return; //error
  54                         }
  55                 }
  56         }
  57         constant = Constant.fromValue(value = computedValue.floatValue());
  58 }
  59 /**
  60  * Code generation for float literal
  61  *
  62  * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  63  * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  64  * @param valueRequired boolean
  65  */
  66 public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
  67         int pc = codeStream.position;
  68         if (valueRequired)
  69                 if ((implicitConversion >> 4) == T_float)
  70                         codeStream.generateInlinedValue(value);
  71                 else
  72                         codeStream.generateConstant(constant, implicitConversion);
  73         codeStream.recordPositionsFrom(pc, this.sourceStart);
  74 }
  75 public TypeBinding literalType(BlockScope scope) {
  76         return FloatBinding;
  77 }
  78 public void traverse(ASTVisitor visitor, BlockScope blockScope) {
  79         visitor.visit(this, blockScope);
  80         visitor.endVisit(this, blockScope);
  81 }
  82 }