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).
  • Constructor Details

    • NumberMath

      public NumberMath()
  • Method Details

    • 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.
    • bitwiseNegate

      public static Number bitwiseNegate(Number left)
    • unaryMinus

      public static Number unaryMinus(Number left)
    • unaryPlus

      public static Number unaryPlus(Number left)
    • isFloatingPoint

      public static boolean isFloatingPoint(Number number)
    • isInteger

      public static boolean isInteger(Number number)
    • isShort

      public static boolean isShort(Number number)
    • isByte

      public static boolean isByte(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)
    • unaryPlusImpl

      protected abstract Number unaryPlusImpl(Number left)
    • bitwiseNegateImpl

      protected Number bitwiseNegateImpl(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)