Copyright (c) 2000, 2011 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2011 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.impl.FloatConstant;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.util.FloatUtil;

public class FloatLiteral extends NumberLiteral {
	
	float value;
	
public FloatLiteral(char[] token, int s, int e) {
	super(token, s, e);
}

@Override
public void computeConstant() {
	Float computedValue;
	boolean containsUnderscores = CharOperation.indexOf('_', this.source) > 0;
	if (containsUnderscores) {
		// remove all underscores from source
		this.source = CharOperation.remove(this.source, '_');
	}
	try {
		computedValue = Float.valueOf(String.valueOf(this.source));
	} catch (NumberFormatException e) {
		// hex floating point literal
		// being rejected by 1.4 libraries where Float.valueOf(...) doesn't handle hex decimal floats
		try {
			float v = FloatUtil.valueOfHexFloatLiteral(this.source);
			if (v == Float.POSITIVE_INFINITY) {
				// error: the number is too large to represent
				return;
			}
			if (Float.isNaN(v)) {
				// error: the number is too small to represent
				return;
			}
			this.value = v;
			this.constant = FloatConstant.fromValue(v);
		} catch (NumberFormatException e1) {
			// if the computation of the constant fails
		}
		return;
	}
	final float floatValue = computedValue.floatValue();
	if (floatValue > Float.MAX_VALUE) {
		// error: the number is too large to represent
		return;
	}
	if (floatValue < Float.MIN_VALUE) {
		// see 1F6IGUU
		// a true 0 only has '0' and '.' in mantissa
		// 1.0e-5000d is non-zero, but underflows to 0
		boolean isHexaDecimal = false;
		label : for (int i = 0; i < this.source.length; i++) { //it is welled formated so just test against '0' and potential . D d
			switch (this.source[i]) {
				case '0' :
				case '.' :
					break;
				case 'x' :
				case 'X' :
					isHexaDecimal = true;
					break;
				case 'e' :
				case 'E' :
				case 'f' :
				case 'F' :
				case 'd' :
				case 'D' :
					if (isHexaDecimal) {
						return;
					}
					// starting the exponent - mantissa is all zero
					// no exponent - mantissa is all zero
					break label;
				case 'p' :
				case 'P' :
					break label;
				default :
					// error: the number is too small to represent
					return;
			}
		}
	}
	this.value = floatValue;
	this.constant = FloatConstant.fromValue(this.value);
}

Code generation for float literal
Params:
currentScope – org.eclipse.jdt.internal.compiler.lookup.BlockScope
codeStream – org.eclipse.jdt.internal.compiler.codegen.CodeStream
valueRequired – boolean/**
 * Code generation for float literal
 *
 * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
 * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
 * @param valueRequired boolean
 */
@Override
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);
}

@Override
public TypeBinding literalType(BlockScope scope) {
	return TypeBinding.FLOAT;
}

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