org.codehaus.groovy.runtime.typehandling

## Class NumberMath

- java.lang.Object
- - org.codehaus.groovy.runtime.typehandling.NumberMath

Direct Known Subclasses:
  BigDecimalMath, BigIntegerMath, FloatingPointMath, IntegerMath, LongMath

    public abstract class NumberMath
    extends Object

Stateless objects used to perform math on the various Number subclasses. Instances are required so that polymorphic calls work properly, but each subclass creates a singleton instance to minimize garbage. All methods must be thread-safe. The design goals of this class are as follows:

1. Support a 'least surprising' math model to scripting language users. This means that exact, or decimal math should be used for default calculations. This scheme assumes that by default, groovy literals with decimal points are instantiated as BigDecimal objects rather than binary floating points (Float, Double).
2. Do not force the appearance of exactness on a number that is by definition not guaranteed to be exact. In particular this means that if an operand in a NumberMath operation is a binary floating point number, ensure that the result remains a binary floating point number (i.e. never automatically promote a binary floating point number to a BigDecimal). This has the effect of preserving the expectations of binary floating point users and helps performance.
3. Provide an implementation that is as close as practical to the Java 1.5 BigDecimal math model which implements precision based floating point decimal math (ANSI X3.274-1996 and ANSI X3.274-1996/AM 1-2000 (section 7.4).

Author:
  Steve Goetze

### Constructor Summary

Constructors
Constructor and Description
`NumberMath()`

### Method Summary

Methods
`static Number` `abs(Number number)`
`protected abstract Number` `absImpl(Number number)`
`static Number` `add(Number left, Number right)`
`abstract Number` `addImpl(Number left, Number right)`
`static Number` `and(Number left, Number right)`
`protected Number` `andImpl(Number left, Number right)`
`static int` `compareTo(Number left, Number right)`
`abstract int` `compareToImpl(Number left, Number right)`
`protected UnsupportedOperationException` `createUnsupportedException(String operation, Number left)`
`static Number` `divide(Number left, Number right)`
`abstract Number` `divideImpl(Number left, Number right)`
`static NumberMath` `getMath(Number left, Number right)` Determine which NumberMath instance to use, given the supplied operands.
`static Number` `intdiv(Number left, Number right)`
`protected Number` `intdivImpl(Number left, Number right)`
`static boolean` `isBigDecimal(Number number)`
`static boolean` `isBigInteger(Number number)`
`static boolean` `isFloatingPoint(Number number)`
`static boolean` `isInteger(Number number)`
`static boolean` `isLong(Number number)`
`static Number` `leftShift(Number left, Number right)` For this operation, consider the operands independently.
`protected Number` `leftShiftImpl(Number left, Number right)`
`static Number` `mod(Number left, Number right)`
`protected Number` `modImpl(Number left, Number right)`
`static Number` `multiply(Number left, Number right)`
`abstract Number` `multiplyImpl(Number left, Number right)`
`static Number` `or(Number left, Number right)`
`protected Number` `orImpl(Number left, Number right)`
`static Number` `rightShift(Number left, Number right)` For this operation, consider the operands independently.
`protected Number` `rightShiftImpl(Number left, Number right)`
`static Number` `rightShiftUnsigned(Number left, Number right)` For this operation, consider the operands independently.
`protected Number` `rightShiftUnsignedImpl(Number left, Number right)`
`static Number` `subtract(Number left, Number right)`
`abstract Number` `subtractImpl(Number left, Number right)`
`static BigDecimal` `toBigDecimal(Number n)`
`static BigInteger` `toBigInteger(Number n)`
`static Number` `unaryMinus(Number left)`
`protected abstract Number` `unaryMinusImpl(Number left)`
`static Number` `xor(Number left, Number right)`
`protected Number` `xorImpl(Number left, Number right)`

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Constructor Detail

#### NumberMath

    public NumberMath()

### Method Detail

#### abs

    public static Number abs(Number number)

#### add

    public static Number add(Number left,
             Number right)

#### subtract

    public static Number subtract(Number left,
                  Number right)

#### multiply

    public static Number multiply(Number left,
                  Number right)

#### divide

    public static Number divide(Number left,
                Number right)

#### compareTo

    public static int compareTo(Number left,
                Number right)

#### or

    public static Number or(Number left,
            Number right)

#### and

    public static Number and(Number left,
             Number right)

#### xor

    public static Number xor(Number left,
             Number right)

#### intdiv

    public static Number intdiv(Number left,
                Number right)

#### mod

    public static Number mod(Number left,
             Number right)

#### leftShift

    public static Number leftShift(Number left,
                   Number right)

For this operation, consider the operands independently. Throw an exception if the right operand (shift distance) is not an integral type. For the left operand (shift value) also require an integral type, but do NOT promote from Integer to Long. This is consistent with Java, and makes sense for the shift operators.

#### rightShift

    public static Number rightShift(Number left,
                    Number right)

For this operation, consider the operands independently. Throw an exception if the right operand (shift distance) is not an integral type. For the left operand (shift value) also require an integral type, but do NOT promote from Integer to Long. This is consistent with Java, and makes sense for the shift operators.

#### rightShiftUnsigned

    public static Number rightShiftUnsigned(Number left,
                            Number right)

For this operation, consider the operands independently. Throw an exception if the right operand (shift distance) is not an integral type. For the left operand (shift value) also require an integral type, but do NOT promote from Integer to Long. This is consistent with Java, and makes sense for the shift operators.

#### unaryMinus

    public static Number unaryMinus(Number left)

#### isFloatingPoint

    public static boolean isFloatingPoint(Number number)

#### isInteger

    public static boolean isInteger(Number number)

#### isLong

    public static boolean isLong(Number number)

#### isBigDecimal

    public static boolean isBigDecimal(Number number)

#### isBigInteger

    public static boolean isBigInteger(Number number)

#### toBigDecimal

    public static BigDecimal toBigDecimal(Number n)

#### toBigInteger

    public static BigInteger toBigInteger(Number n)

#### getMath

    public static NumberMath getMath(Number left,
                     Number right)

Determine which NumberMath instance to use, given the supplied operands. This method implements the type promotion rules discussed in the documentation. Note that by the time this method is called, any Byte, Character or Short operands will have been promoted to Integer. For reference, here is the promotion matrix: bD bI D F L I bD bD bD D D bD bD bI bD bI D D bI bI D D D D D D D F D D D D D D L bD bI D D L L I bD bI D D L I Note that for division, if either operand isFloatingPoint, the result will be floating. Otherwise, the result is BigDecimal

#### absImpl

    protected abstract Number absImpl(Number number)

#### addImpl

    public abstract Number addImpl(Number left,
                 Number right)

#### subtractImpl

    public abstract Number subtractImpl(Number left,
                      Number right)

#### multiplyImpl

    public abstract Number multiplyImpl(Number left,
                      Number right)

#### divideImpl

    public abstract Number divideImpl(Number left,
                    Number right)

#### compareToImpl

    public abstract int compareToImpl(Number left,
                    Number right)

#### unaryMinusImpl

    protected abstract Number unaryMinusImpl(Number left)

#### orImpl

    protected Number orImpl(Number left,
                Number right)

#### andImpl

    protected Number andImpl(Number left,
                 Number right)

#### xorImpl

    protected Number xorImpl(Number left,
                 Number right)

#### modImpl

    protected Number modImpl(Number left,
                 Number right)

#### intdivImpl

    protected Number intdivImpl(Number left,
                    Number right)

#### leftShiftImpl

    protected Number leftShiftImpl(Number left,
                       Number right)

#### rightShiftImpl

    protected Number rightShiftImpl(Number left,
                        Number right)

#### rightShiftUnsignedImpl

    protected Number rightShiftUnsignedImpl(Number left,
                                Number right)

#### createUnsupportedException

    protected UnsupportedOperationException createUnsupportedException(String operation,
                                                           Number left)