IntLiteral.java

/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.jsdt.internal.compiler.ast;

import org.eclipse.wst.jsdt.core.ast.IASTNode;
import org.eclipse.wst.jsdt.core.ast.IIntLiteral;
import org.eclipse.wst.jsdt.internal.compiler.ASTVisitor;
import org.eclipse.wst.jsdt.internal.compiler.impl.Constant;
import org.eclipse.wst.jsdt.internal.compiler.impl.DoubleConstant;
import org.eclipse.wst.jsdt.internal.compiler.impl.IntConstant;
import org.eclipse.wst.jsdt.internal.compiler.lookup.BlockScope;
import org.eclipse.wst.jsdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.wst.jsdt.internal.compiler.parser.ScannerHelper;

public class IntLiteral extends NumberLiteral implements IIntLiteral {
	public int value;


	static final Constant FORMAT_ERROR = DoubleConstant.fromValue(1.0/0.0); // NaN;
public IntLiteral(char[] token, int s, int e) {
	super(token, s,e);
}
public IntLiteral(char[] token, int s,int e, int value) {
	this(token, s,e);
	this.value = value;
}
public IntLiteral(int intValue) {
	//special optimized constructor : the cst is the argument

	//value that should not be used
	//	tokens = null ;
	//	sourceStart = 0;
	//	sourceEnd = 0;
	super(null,0,0);
	constant = IntConstant.fromValue(intValue);
	value = intValue;

}
public void computeConstant() {
	//a special constant is use for the potential Integer.MAX_VALUE+1
	//which is legal if used with a - as prefix....cool....
	//notice that Integer.MIN_VALUE  == -2147483648


	int length = source.length;
	long computedValue = 0L;
	if (source[0] == '0')
	{	if (length == 1) {	constant = IntConstant.fromValue(0); return ;}
		final int shift,radix;
		int maxDigit=16;
		int j ;
		if ( (source[1] == 'x') || (source[1] == 'X') )
		{	shift = 4 ; j = 2; radix = 16; maxDigit=18;}
		else
		{	shift = 3 ; j = 1; radix = 8;}
		if (length>maxDigit)
			return ;
		while (source[j]=='0')
		{	j++; //jump over redondant zero
			if (j == length)
			{	//watch for 000000000000000000
				constant = IntConstant.fromValue(value = (int)computedValue);
				return ;}}

		while (j<length)
		{	int digitValue ;
			if ((digitValue = ScannerHelper.digit(source[j++],radix))	< 0 )
			{	constant = FORMAT_ERROR; return ;}
			computedValue = (computedValue<<shift) | digitValue ;
//			if (computedValue > MAX) return /*constant stays null*/ ;
		}	}
	else
	{	//-----------regular case : radix = 10-----------
		for (int i = 0 ; i < length;i++)
		{	int digitValue ;
			if ((digitValue = ScannerHelper.digit(source[i],10))	< 0 )
			{	constant = FORMAT_ERROR; return ;}
			computedValue = 10*computedValue + digitValue;
//			if (computedValue > MAX) return /*constant stays null*/ ; 
		}}

	constant = IntConstant.fromValue(value = (int)computedValue);

}
public TypeBinding literalType(BlockScope scope) {
	if(scope == null)
		return TypeBinding.INT;
	return scope.getJavaLangNumber();

}
public final boolean mayRepresentMIN_VALUE(){
	//a special autorized int literral is 2147483648
	//which is ONE over the limit. This special case
	//only is used in combinaison with - to denote
	//the minimal value of int -2147483648

	return ((source.length == 10) &&
			(source[0] == '2') &&
			(source[1] == '1') &&
			(source[2] == '4') &&
			(source[3] == '7') &&
			(source[4] == '4') &&
			(source[5] == '8') &&
			(source[6] == '3') &&
			(source[7] == '6') &&
			(source[8] == '4') &&
			(source[9] == '8') &&
			(((this.bits & ASTNode.ParenthesizedMASK) >> ASTNode.ParenthesizedSHIFT) == 0));
}
public TypeBinding resolveType(BlockScope scope) {
	// the format may be incorrect while the scanner could detect
	// such an error only on painfull tests...easier and faster here

	TypeBinding tb = super.resolveType(scope);
	if (constant == FORMAT_ERROR) {
		constant = Constant.NotAConstant;
		scope.problemReporter().constantOutOfFormat(this);
		this.resolvedType = null;
		return null;
	}
	return tb;
}
public StringBuffer printExpression(int indent, StringBuffer output){

	if (source == null) {
	/* special optimized IntLiteral that are created by the compiler */
		return output.append(String.valueOf(value));
	}
	return super.printExpression(indent, output);
}

public void traverse(ASTVisitor visitor, BlockScope scope) {
	visitor.visit(this, scope);
	visitor.endVisit(this, scope);
}
public int getASTType() {
	return IASTNode.INT_LITERAL;

}

public static IntLiteral getOne()
{
	return new IntLiteral(new char[]{'1'},0,0,1);//used for ++ and --
}

}