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 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package com.sun.tools.javac.util;

import com.sun.tools.javac.code.Type;

Utilities for operating on constant values.
This is NOT part of any supported API.
If you write code that depends on this, you do so at your own risk.
This code and its internal interfaces are subject to change or
deletion without notice.
/**
 * Utilities for operating on constant values.
 *
 * <p><b>This is NOT part of any supported API.
 * If you write code that depends on this, you do so at your own risk.
 * This code and its internal interfaces are subject to change or
 * deletion without notice.</b>
 */
public class Constants {

    
Converts a constant in internal representation (in which
boolean, char, byte, short, and int are each represented by an
Integer) into standard representation.  Other values (including
null) are returned unchanged.
/**
     * Converts a constant in internal representation (in which
     * boolean, char, byte, short, and int are each represented by an
     * Integer) into standard representation.  Other values (including
     * null) are returned unchanged.
     */
    public static Object decode(Object value, Type type) {
        if (value instanceof Integer) {
            int i = (Integer) value;
            switch (type.getTag()) {
            case BOOLEAN:  return i != 0;
            case CHAR:     return (char) i;
            case BYTE:     return (byte) i;
            case SHORT:    return (short) i;
            }
        }
        return value;
    }

    
Returns a string representation of a constant value (given in
internal representation), quoted and formatted as in Java source.
/**
     * Returns a string representation of a constant value (given in
     * internal representation), quoted and formatted as in Java source.
     */
    public static String format(Object value, Type type) {
        value = decode(value, type);
        switch (type.getTag()) {
        case BYTE:      return formatByte((Byte) value);
        case LONG:      return formatLong((Long) value);
        case FLOAT:     return formatFloat((Float) value);
        case DOUBLE:    return formatDouble((Double) value);
        case CHAR:      return formatChar((Character) value);
        }
        if (value instanceof String)
            return formatString((String) value);
        return value + "";
    }

    
Returns a string representation of a constant value (given in
standard wrapped representation), quoted and formatted as in
Java source.
/**
     * Returns a string representation of a constant value (given in
     * standard wrapped representation), quoted and formatted as in
     * Java source.
     */
    public static String format(Object value) {
        if (value instanceof Byte)      return formatByte((Byte) value);
        if (value instanceof Short)     return formatShort((Short) value);
        if (value instanceof Long)      return formatLong((Long) value);
        if (value instanceof Float)     return formatFloat((Float) value);
        if (value instanceof Double)    return formatDouble((Double) value);
        if (value instanceof Character) return formatChar((Character) value);
        if (value instanceof String)    return formatString((String) value);
        if (value instanceof Integer ||
            value instanceof Boolean)   return value.toString();
        else
            throw new IllegalArgumentException("Argument is not a primitive type or a string; it " +
                                               ((value == null) ?
                                                "is a null value." :
                                                "has class " +
                                                value.getClass().getName()) + "." );
    }

    private static String formatByte(byte b) {
        return String.format("(byte)0x%02x", b);
    }

    private static String formatShort(short s) {
        return String.format("(short)%d", s);
    }

    private static String formatLong(long lng) {
        return lng + "L";
    }

    private static String formatFloat(float f) {
        if (Float.isNaN(f))
            return "0.0f/0.0f";
        else if (Float.isInfinite(f))
            return (f < 0) ? "-1.0f/0.0f" : "1.0f/0.0f";
        else
            return f + "f";
    }

    private static String formatDouble(double d) {
        if (Double.isNaN(d))
            return "0.0/0.0";
        else if (Double.isInfinite(d))
            return (d < 0) ? "-1.0/0.0" : "1.0/0.0";
        else
            return d + "";
    }

    private static String formatChar(char c) {
        return '\'' + Convert.quote(c) + '\'';
    }

    private static String formatString(String s) {
        return '"' + Convert.quote(s) + '"';
    }
}