/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.compiler.ast;

import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
import net.sourceforge.phpdt.internal.compiler.impl.Constant;
import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;

public class FloatLiteral extends NumberLiteral {
	float value;

	final static float Float_MIN_VALUE = Float.intBitsToFloat(1); // work-around
																	// VAJ
																	// problem
																	// 1F6IGUU

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

	public void computeConstant() {

		// the source is correctly formated so the exception should never occurs

		Float computedValue;
		try {
			computedValue = Float.valueOf(String.valueOf(source));
		} catch (NumberFormatException e) {
			return;
		}

		if (computedValue.doubleValue() > Float.MAX_VALUE) {
			return; // may be Infinity
		}
		if (computedValue.floatValue() < Float_MIN_VALUE) {
			// see 1F6IGUU
			// only a true 0 can be made of zeros
			// 1.00000000e-46f is illegal ....
			label: for (int i = 0; i < source.length; i++) {
				switch (source[i]) {
				case '.':
				case 'f':
				case 'F':
				case '0':
					break;
				case 'e':
				case 'E':
					break label; // exposant are valid !....
				default:
					return; // error

				}
			}
		}
		constant = Constant.fromValue(value = computedValue.floatValue());
	}

	/**
	 * Code generation for float literal
	 * 
	 * @param currentScope
	 *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
	 * @param codeStream
	 *            net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
	 * @param valueRequired
	 *            boolean
	 */
	// public void generateCode(BlockScope currentScope, CodeStream codeStream,
	// boolean valueRequired) {
	// int pc = codeStream.position;
	// if (valueRequired)
	// if ((implicitConversion >> 4) == T_float)
	// codeStream.generateInlinedValue(value);
	// else
	// codeStream.generateConstant(constant, implicitConversion);
	// codeStream.recordPositionsFrom(pc, this.sourceStart);
	// }
	public TypeBinding literalType(BlockScope scope) {
		return FloatBinding;
	}

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