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

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 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 net.sourceforge.phpdt.internal.compiler.ast;
  12
  13 import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
  14 import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
  15 import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
  16
  17 public class NullLiteral extends MagicLiteral {
  18
  19         static final char[] source = { 'n', 'u', 'l', 'l' };
  20
  21         public NullLiteral(int s, int e) {
  22
  23                 super(s, e);
  24         }
  25
  26         public void computeConstant() {
  27
  28                 constant = NotAConstant;
  29         }
  30
  31         /**
  32          * Code generation for the null literal
  33          *
  34          * @param currentScope
  35          *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
  36          * @param codeStream
  37          *            net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
  38          * @param valueRequired
  39          *            boolean
  40          */
  41         // public void generateCode(BlockScope currentScope, CodeStream codeStream,
  42         // boolean valueRequired) {
  43         // int pc = codeStream.position;
  44         // if (valueRequired)
  45         // codeStream.aconst_null();
  46         // codeStream.recordPositionsFrom(pc, this.sourceStart);
  47         // }
  48         public TypeBinding literalType(BlockScope scope) {
  49                 return NullBinding;
  50         }
  51
  52         /**
  53          *
  54          */
  55         public char[] source() {
  56                 return source;
  57         }
  58
  59         public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope scope) {
  60                 visitor.visit(this, scope);
  61                 visitor.endVisit(this, scope);
  62         }
  63 }