net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/compiler/ast/FloatLiteral.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v0.5
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v05.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  ******************************************************************************/
  11 package net.sourceforge.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.codegen.CodeStream;
  15 import net.sourceforge.phpdt.internal.compiler.impl.Constant;
  16 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  17 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  18
  19 public class FloatLiteral extends NumberLiteral {
  20         float value;
  21         final static float Float_MIN_VALUE = Float.intBitsToFloat(1); // work-around VAJ problem 1F6IGUU
  22 public FloatLiteral(char[] token, int s, int e) {
  23         super(token, s,e);
  24 }
  25 public void computeConstant() {
  26
  27         //the source is correctly formated so the exception should never occurs
  28
  29         Float computedValue;
  30         try {
  31                 computedValue = Float.valueOf(String.valueOf(source));
  32         } catch (NumberFormatException e) {
  33                 return;
  34         }
  35
  36         if (computedValue.doubleValue() > Float.MAX_VALUE){
  37                 return; //may be Infinity
  38         }
  39         if (computedValue.floatValue() < Float_MIN_VALUE){
  40                 // see 1F6IGUU
  41                 //only a true 0 can be made of zeros
  42                 //1.00000000e-46f is illegal ....
  43                 label : for (int i = 0; i < source.length; i++) {
  44                         switch (source[i]) {
  45                                 case '.' :
  46                                 case 'f' :
  47                                 case 'F' :
  48                                 case '0' :
  49                                         break;
  50                                 case 'e' :
  51                                 case 'E' :
  52                                         break label; //exposant are valid !....
  53                                 default :
  54                                         return; //error
  55
  56
  57                         }
  58                 }
  59         }
  60         constant = Constant.fromValue(value = computedValue.floatValue());
  61 }
  62 /**
  63  * Code generation for float literal
  64  *
  65  * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  66  * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  67  * @param valueRequired boolean
  68  */
  69 public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
  70         int pc = codeStream.position;
  71         if (valueRequired)
  72                 if ((implicitConversion >> 4) == T_float)
  73                         codeStream.generateInlinedValue(value);
  74                 else
  75                         codeStream.generateConstant(constant, implicitConversion);
  76         codeStream.recordPositionsFrom(pc, this.sourceStart);
  77 }
  78 public TypeBinding literalType(BlockScope scope) {
  79         return FloatBinding;
  80 }
  81 public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope blockScope) {
  82         visitor.visit(this, blockScope);
  83         visitor.endVisit(this, blockScope);
  84 }
  85 }