com.google.common.primitives

Class UnsignedLongs


  • @Beta
 @GwtCompatible
public final class UnsignedLongs
extends Object
    Static utility methods pertaining to long primitives that interpret values as unsigned (that is, any negative value x is treated as the positive value 2^64 + x). The methods for which signedness is not an issue are in Longs, as well as signed versions of methods for which signedness is an issue.

    In addition, this class provides several static methods for converting a long to a String and a String to a long that treat the long as an unsigned number.

    Users of these utilities must be extremely careful not to mix up signed and unsigned long values. When possible, it is recommended that the UnsignedLong wrapper class be used, at a small efficiency penalty, to enforce the distinction in the type system.

    See the Guava User Guide article on unsigned primitive utilities.

    Since:
    10.0

    • Field Summary

      Fields

      Modifier and Type Field and Description
      static long MAX_VALUE
       

    • Method Summary

      Methods

      Modifier and Type Method and Description
      static int compare(long a, long b)
      Compares the two specified long values, treating them as unsigned values between 0 and 2^64 - 1 inclusive.
      static long decode(String stringValue)
      Returns the unsigned long value represented by the given string.
      static long divide(long dividend, long divisor)
      Returns dividend / divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
      static String join(String separator, long... array)
      Returns a string containing the supplied unsigned long values separated by separator.
      static Comparator<long[]> lexicographicalComparator()
      Returns a comparator that compares two arrays of unsigned long values lexicographically.
      static long max(long... array)
      Returns the greatest value present in array, treating values as unsigned.
      static long min(long... array)
      Returns the least value present in array, treating values as unsigned.
      static long parseUnsignedLong(String s)
      Returns the unsigned long value represented by the given decimal string.
      static long parseUnsignedLong(String s, int radix)
      Returns the unsigned long value represented by a string with the given radix.
      static long remainder(long dividend, long divisor)
      Returns dividend % divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
      static String toString(long x)
      Returns a string representation of x, where x is treated as unsigned.
      static String toString(long x, int radix)
      Returns a string representation of x for the given radix, where x is treated as unsigned.

    • Method Detail

      • compare

        public static int compare(long a,
                          long b)
        Compares the two specified long values, treating them as unsigned values between 0 and 2^64 - 1 inclusive.
        Parameters:
        a - the first unsigned long to compare
        b - the second unsigned long to compare
        Returns:
        a negative value if a is less than b; a positive value if a is greater than b; or zero if they are equal

      • min

        public static long min(long... array)
        Returns the least value present in array, treating values as unsigned.
        Parameters:
        array - a nonempty array of unsigned long values
        Returns:
        the value present in array that is less than or equal to every other value in the array according to compare(long, long)
        Throws:
        IllegalArgumentException - if array is empty

      • max

        public static long max(long... array)
        Returns the greatest value present in array, treating values as unsigned.
        Parameters:
        array - a nonempty array of unsigned long values
        Returns:
        the value present in array that is greater than or equal to every other value in the array according to compare(long, long)
        Throws:
        IllegalArgumentException - if array is empty

      • join

        public static String join(String separator,
                          long... array)
        Returns a string containing the supplied unsigned long values separated by separator. For example, join("-", 1, 2, 3) returns the string "1-2-3".
        Parameters:
        separator - the text that should appear between consecutive values in the resulting string (but not at the start or end)
        array - an array of unsigned long values, possibly empty

      • lexicographicalComparator

        public static Comparator<long[]> lexicographicalComparator()
        Returns a comparator that compares two arrays of unsigned long values lexicographically. That is, it compares, using compare(long, long)), the first pair of values that follow any common prefix, or when one array is a prefix of the other, treats the shorter array as the lesser. For example, [] < [1L] < [1L, 2L] < [2L] < [1L << 63].

        The returned comparator is inconsistent with Object.equals(Object) (since arrays support only identity equality), but it is consistent with Arrays.equals(long[], long[]).

        See Also:
        Lexicographical order article at Wikipedia

      • divide

        public static long divide(long dividend,
                          long divisor)
        Returns dividend / divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
        Parameters:
        dividend - the dividend (numerator)
        divisor - the divisor (denominator)
        Throws:
        ArithmeticException - if divisor is 0

      • remainder

        public static long remainder(long dividend,
                             long divisor)
        Returns dividend % divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
        Parameters:
        dividend - the dividend (numerator)
        divisor - the divisor (denominator)
        Throws:
        ArithmeticException - if divisor is 0
        Since:
        11.0

      • decode

        public static long decode(String stringValue)
        Returns the unsigned long value represented by the given string. Accepts a decimal, hexadecimal, or octal number given by specifying the following prefix:
        • 0xHexDigits
        • 0XHexDigits
        • #HexDigits
        • 0OctalDigits
        Throws:
        NumberFormatException - if the string does not contain a valid unsigned long value
        Since:
        13.0

      • parseUnsignedLong

        public static long parseUnsignedLong(String s,
                                     int radix)
        Returns the unsigned long value represented by a string with the given radix.
        Parameters:
        s - the string containing the unsigned long representation to be parsed.
        radix - the radix to use while parsing s
        Throws:
        NumberFormatException - if the string does not contain a valid unsigned long with the given radix, or if radix is not between Character.MIN_RADIX and Character.MAX_RADIX.
        NullPointerException - if s is null (in contrast to Long.parseLong(String))

      • toString

        public static String toString(long x)
        Returns a string representation of x, where x is treated as unsigned.

      • toString

        public static String toString(long x,
                              int radix)
        Returns a string representation of x for the given radix, where x is treated as unsigned.
        Parameters:
        x - the value to convert to a string.
        radix - the radix to use while working with x
        Throws:
        IllegalArgumentException - if radix is not between Character.MIN_RADIX and Character.MAX_RADIX.