panda.lang.mutable.MutableDouble Maven / Gradle / Ivy
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package panda.lang.mutable;
/**
* A mutable double wrapper.
*
* Note that as MutableDouble does not extend Double, it is not treated by String.format as a Double parameter.
*
*/
public class MutableDouble extends Number implements Comparable, Mutable {
/**
* Required for serialization support.
*
* @see java.io.Serializable
*/
private static final long serialVersionUID = 1587163916L;
/** The mutable value. */
private double value;
/**
* Constructs a new MutableDouble with the default value of zero.
*/
public MutableDouble() {
super();
}
/**
* Constructs a new MutableDouble with the specified value.
*
* @param value the initial value to store
*/
public MutableDouble(double value) {
super();
this.value = value;
}
/**
* Constructs a new MutableDouble with the specified value.
*
* @param value the initial value to store, not null
* @throws NullPointerException if the object is null
*/
public MutableDouble(Number value) {
super();
this.value = value.doubleValue();
}
/**
* Constructs a new MutableDouble parsing the given string.
*
* @param value the string to parse, not null
* @throws NumberFormatException if the string cannot be parsed into a double
*/
public MutableDouble(String value) throws NumberFormatException {
super();
this.value = Double.parseDouble(value);
}
// -----------------------------------------------------------------------
/**
* Gets the value as a Double instance.
*
* @return the value as a Double, never null
*/
public Double getValue() {
return Double.valueOf(this.value);
}
/**
* Sets the value.
*
* @param value the value to set
*/
public void setValue(double value) {
this.value = value;
}
/**
* Sets the value from any Number instance.
*
* @param value the value to set, not null
* @throws NullPointerException if the object is null
*/
public void setValue(Number value) {
this.value = value.doubleValue();
}
// -----------------------------------------------------------------------
/**
* Checks whether the double value is the special NaN value.
*
* @return true if NaN
*/
public boolean isNaN() {
return Double.isNaN(value);
}
/**
* Checks whether the double value is infinite.
*
* @return true if infinite
*/
public boolean isInfinite() {
return Double.isInfinite(value);
}
// -----------------------------------------------------------------------
/**
* Increments the value.
*/
public void increment() {
value++;
}
/**
* Decrements the value.
*/
public void decrement() {
value--;
}
// -----------------------------------------------------------------------
/**
* Adds a value to the value of this instance.
*
* @param operand the value to add
*/
public void add(double operand) {
this.value += operand;
}
/**
* Adds a value to the value of this instance.
*
* @param operand the value to add, not null
* @throws NullPointerException if the object is null
*/
public void add(Number operand) {
this.value += operand.doubleValue();
}
/**
* Subtracts a value from the value of this instance.
*
* @param operand the value to subtract, not null
*/
public void subtract(double operand) {
this.value -= operand;
}
/**
* Subtracts a value from the value of this instance.
*
* @param operand the value to subtract, not null
* @throws NullPointerException if the object is null
*/
public void subtract(Number operand) {
this.value -= operand.doubleValue();
}
// -----------------------------------------------------------------------
// shortValue and byteValue rely on Number implementation
/**
* Returns the value of this MutableDouble as an int.
*
* @return the numeric value represented by this object after conversion to type int.
*/
@Override
public int intValue() {
return (int)value;
}
/**
* Returns the value of this MutableDouble as a long.
*
* @return the numeric value represented by this object after conversion to type long.
*/
@Override
public long longValue() {
return (long)value;
}
/**
* Returns the value of this MutableDouble as a float.
*
* @return the numeric value represented by this object after conversion to type float.
*/
@Override
public float floatValue() {
return (float)value;
}
/**
* Returns the value of this MutableDouble as a double.
*
* @return the numeric value represented by this object after conversion to type double.
*/
@Override
public double doubleValue() {
return value;
}
// -----------------------------------------------------------------------
/**
* Gets this mutable as an instance of Double.
*
* @return a Double instance containing the value from this mutable, never null
*/
public Double toDouble() {
return Double.valueOf(doubleValue());
}
// -----------------------------------------------------------------------
/**
* Compares this object against the specified object. The result is true if and
* only if the argument is not null and is a Double object that
* represents a double that has the identical bit pattern to the bit pattern of the double
* represented by this object. For this purpose, two double values are considered
* to be the same if and only if the method {@link Double#doubleToLongBits(double)}returns the
* same long value when applied to each.
*
* Note that in most cases, for two instances of class Double,d1 and
* d2, the value of d1.equals(d2) is true if and only if
*
*
*
* d1.doubleValue() == d2.doubleValue()
*
*
*
*
* also has the value true. However, there are two exceptions:
*
* - If
d1 and d2 both represent Double.NaN, then the
* equals method returns true, even though
* Double.NaN==Double.NaN has the value false.
* - If
d1 represents +0.0 while d2 represents
* -0.0, or vice versa, the equal test has the value
* false, even though +0.0==-0.0 has the value true. This
* allows hashtables to operate properly.
*
*
* @param obj the object to compare with, null returns false
* @return true if the objects are the same; false otherwise.
*/
@Override
public boolean equals(Object obj) {
return obj instanceof MutableDouble
&& Double.doubleToLongBits(((MutableDouble)obj).value) == Double.doubleToLongBits(value);
}
/**
* Returns a suitable hash code for this mutable.
*
* @return a suitable hash code
*/
@Override
public int hashCode() {
long bits = Double.doubleToLongBits(value);
return (int)(bits ^ bits >>> 32);
}
// -----------------------------------------------------------------------
/**
* Compares this mutable to another in ascending order.
*
* @param other the other mutable to compare to, not null
* @return negative if this is less, zero if equal, positive if greater
*/
public int compareTo(MutableDouble other) {
double anotherVal = other.value;
return Double.compare(value, anotherVal);
}
// -----------------------------------------------------------------------
/**
* Returns the String value of this mutable.
*
* @return the mutable value as a string
*/
@Override
public String toString() {
return String.valueOf(value);
}
}