ConversionUtils.java

/*
 * Copyright (c) 2007, 2018, 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.
 *
 * 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package nsk.share.jpda;

/*
Static methods checking whether given primitive type value can be
converted to another primitive type without information loss

Note:
the spec defines following 2 types of primitive values conversions:

Widening primitive conversions (don't loose information, but may lose precision):
    * byte to short, int, long, float, or double
    * short to int, long, float, or double
    * char to int, long, float, or double
    * int to long, float, or double
    * long to float or double
    * float to double

Narrowing primitive conversions (may loose information and may loose precision):
    * byte to char
    * short to byte or char
    * char to byte or short
    * int to byte, short, or char
    * long to byte, short, char, or int
    * float to byte, short, char, int, or long
    * double to byte, short, char, int, long, or float

Examples:
    Conversions (int)1234567890 -> (float)1.23456794E9 and (float)1.5 -> (int)1 loose precision.
    Conversion  (byte)-1 -> (char) ffff and (double)Double.MAX_VALUE -> (int)Integer.MAX_VALUE loose information.

(See the "JavaTM Language Specification" section 5.2 for more information
on assignment compatibility)
 */
public class ConversionUtils {

    /*
     * Methods checking that value can be converted to the value of the
     * same type (like 'informationLossByteToByte') were added to simplify
     * clients coding (when this methods exist clients shouldn't handle this case
     * in a specific way)
     */

    /*
     * Byte
     */
    public static boolean informationLossByteToByte(Byte value) {
        return false;
    }

    public static boolean informationLossByteToShort(Byte value) {
        return false;
    }

    public static boolean informationLossByteToChar(Byte value) {
        return (value.byteValue() > Character.MAX_VALUE) || (value.byteValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossByteToInt(Byte value) {
        return false;
    }

    public static boolean informationLossByteToLong(Byte value) {
        return false;
    }

    public static boolean informationLossByteToFloat(Byte value) {
        return false;
    }

    public static boolean informationLossByteToDouble(Byte value) {
        return false;
    }

    /*
     * Short
     */
    public static boolean informationLossShortToShort(Short value) {
        return false;
    }

    public static boolean informationLossShortToByte(Short value) {
        return (value.shortValue() > Byte.MAX_VALUE) || (value.shortValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossShortToChar(Short value) {
        return (value.shortValue() > Character.MAX_VALUE) || (value.shortValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossShortToInt(Short value) {
        return false;
    }

    public static boolean informationLossShortToLong(Short value) {
        return false;
    }

    public static boolean informationLossShortToFloat(Short value) {
        return false;
    }

    public static boolean informationLossShortToDouble(Short value) {
        return false;
    }

    /*
     * Char
     */
    public static boolean informationLossCharToChar(Character value) {
        return false;
    }

    public static boolean informationLossCharToByte(Character value) {
        return (value.charValue() > Byte.MAX_VALUE) || (value.charValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossCharToShort(Character value) {
        return (value.charValue() > Short.MAX_VALUE) || (value.charValue() < Short.MIN_VALUE);
    }

    public static boolean informationLossCharToInt(Character value) {
        return false;
    }

    public static boolean informationLossCharToLong(Character value) {
        return false;
    }

    public static boolean informationLossCharToFloat(Character value) {
        return false;
    }

    public static boolean informationLossCharToDouble(Character value) {
        return false;
    }

    /*
     * Integer
     */
    public static boolean informationLossIntToInt(Integer value) {
        return false;
    }

    public static boolean informationLossIntToByte(Integer value) {
        return (value.intValue() > Byte.MAX_VALUE) || (value.intValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossIntToShort(Integer value) {
        return (value.intValue() > Short.MAX_VALUE) || (value.intValue() < Short.MIN_VALUE);
    }

    public static boolean informationLossIntToChar(Integer value) {
        return (value.intValue() > Character.MAX_VALUE) || (value.intValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossIntToLong(Integer value) {
        return false;
    }

    public static boolean informationLossIntToFloat(Integer value) {
        return false;
    }

    public static boolean informationLossIntToDouble(Integer value) {
        return false;
    }

    /*
     * Long
     */
    public static boolean informationLossLongToLong(Long value) {
        return false;
    }

    public static boolean informationLossLongToByte(Long value) {
        return (value.longValue() > Byte.MAX_VALUE) || (value.longValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossLongToShort(Long value) {
        return (value.longValue() > Short.MAX_VALUE) || (value.longValue() < Short.MIN_VALUE);
    }

    public static boolean informationLossLongToChar(Long value) {
        return (value.longValue() > Character.MAX_VALUE) || (value.longValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossLongToInt(Long value) {
        return (value.longValue() > Integer.MAX_VALUE) || (value.longValue() < Integer.MIN_VALUE);
    }

    public static boolean informationLossLongToFloat(Long value) {
        return false;
    }

    public static boolean informationLossLongToDouble(Long value) {
        return false;
    }

    /*
     * Float
     */
    public static boolean informationLossFloatToFloat(Float value) {
        return false;
    }

    public static boolean informationLossFloatToByte(Float value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.floatValue() > Byte.MAX_VALUE) || (value.floatValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossFloatToShort(Float value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.floatValue() > Short.MAX_VALUE) || (value.floatValue() < Short.MIN_VALUE);
    }

    public static boolean informationLossFloatToChar(Float value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.floatValue() > Character.MAX_VALUE) || (value.floatValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossFloatToInt(Float value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.floatValue() > Integer.MAX_VALUE) || (value.floatValue() < Integer.MIN_VALUE)
                || ((int)value.floatValue() != value.floatValue());
    }

    public static boolean informationLossFloatToLong(Float value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.floatValue() > Long.MAX_VALUE) || (value.floatValue() < Long.MIN_VALUE)
                || ((long)value.floatValue() != value.floatValue());
    }

    public static boolean informationLossFloatToDouble(Float value) {
        return false;
    }


    /*
     * Double
     */
    public static boolean informationLossDoubleToDouble(Double value) {
        return false;
    }

    public static boolean informationLossDoubleToByte(Double value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.doubleValue() > Byte.MAX_VALUE) || (value.doubleValue() < Byte.MIN_VALUE);
    }

    public static boolean informationLossDoubleToShort(Double value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.doubleValue() > Short.MAX_VALUE) || (value.doubleValue() < Short.MIN_VALUE);
    }

    public static boolean informationLossDoubleToChar(Double value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.doubleValue() > Character.MAX_VALUE) || (value.doubleValue() < Character.MIN_VALUE);
    }

    public static boolean informationLossDoubleToInt(Double value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.doubleValue() > Integer.MAX_VALUE) || (value.doubleValue() < Integer.MIN_VALUE);
    }

    public static boolean informationLossDoubleToLong(Double value) {
        if (value.isInfinite())
            return true;

        if (value.isNaN())
            return true;

        return (value.doubleValue() > Long.MAX_VALUE) || (value.doubleValue() < Long.MIN_VALUE)
                || ((long)value.doubleValue() != value.doubleValue());
    }

    public static boolean informationLossDoubleToFloat(Double value) {
        if (value.isInfinite())
            return false;

        if (value.isNaN())
            return false;

        float f = (float) value.doubleValue();

        return f != value.doubleValue();
    }
}