CharLiteral.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 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.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.impl.CharConstant;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.parser.ScannerHelper;

public class CharLiteral extends NumberLiteral {

	char value;

	public CharLiteral(char[] token, int s, int e) {
		super(token, s, e);
		computeValue();
	}

	public void computeConstant() {
		//The source is a  char[3] first and last char are '
		//This is true for both regular char AND unicode char
		//BUT not for escape char like '\b' which are char[4]....
		this.constant= CharConstant.fromValue(this.value);
	}

	private void computeValue() {
		//The source is a  char[3] first and last char are '
		//This is true for both regular char AND unicode char
		//BUT not for escape char like '\b' which are char[4]....
		if ((this.value= this.source[1]) != '\\')
			return;
		char digit;
		switch (digit= this.source[2]) {
			case 'b':
				this.value= '\b';
				break;
			case 't':
				this.value= '\t';
				break;
			case 'n':
				this.value= '\n';
				break;
			case 'f':
				this.value= '\f';
				break;
			case 'r':
				this.value= '\r';
				break;
			case '\"':
				this.value= '\"';
				break;
			case '\'':
				this.value= '\'';
				break;
			case '\\':
				this.value= '\\';
				break;
			default: //octal (well-formed: ended by a ' )
				int number= ScannerHelper.getNumericValue(digit);
				if ((digit= this.source[3]) != '\'')
					number= (number * 8) + ScannerHelper.getNumericValue(digit);
				else {
					this.constant= CharConstant.fromValue(this.value= (char)number);
					break;
				}
				if ((digit= this.source[4]) != '\'')
					number= (number * 8) + ScannerHelper.getNumericValue(digit);
				this.value= (char)number;
				break;
		}
	}

	/**
	 * CharLiteral code generation
	 * 
	 * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
	 * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
	 * @param valueRequired boolean
	 */
	public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
		int pc= codeStream.position;
		if (valueRequired) {
			codeStream.generateConstant(this.constant, this.implicitConversion);
		}
		codeStream.recordPositionsFrom(pc, this.sourceStart);
	}

	public TypeBinding literalType(BlockScope scope) {
		return TypeBinding.CHAR;
	}

	public void traverse(ASTVisitor visitor, BlockScope blockScope) {
		visitor.visit(this, blockScope);
		visitor.endVisit(this, blockScope);
	}
}