@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.
Modifier and Type | Field and Description |
---|---|
static long |
MAX_VALUE |
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. |
public static final long MAX_VALUE
@CheckReturnValue 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.
a
- the first unsigned long
to compareb
- the second unsigned long
to comparea
is less than b
; a positive value if a
is greater than b
; or zero if they are equal@CheckReturnValue public static long min(long... array)
Returns the least value present in array
, treating values as unsigned.
array
- a nonempty array of unsigned long
valuesarray
that is less than or equal to every other value in the array according to compare(long, long)
IllegalArgumentException
- if array
is empty@CheckReturnValue public static long max(long... array)
Returns the greatest value present in array
, treating values as unsigned.
array
- a nonempty array of unsigned long
valuesarray
that is greater than or equal to every other value in the array according to compare(long, long)
IllegalArgumentException
- if array
is empty@CheckReturnValue 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"
.
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@CheckReturnValue 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[])
.
@CheckReturnValue public static long divide(long dividend, long divisor)
Returns dividend / divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
dividend
- the dividend (numerator)divisor
- the divisor (denominator)ArithmeticException
- if divisor is 0@CheckReturnValue public static long remainder(long dividend, long divisor)
Returns dividend % divisor, where the dividend and divisor are treated as unsigned 64-bit quantities.
dividend
- the dividend (numerator)divisor
- the divisor (denominator)ArithmeticException
- if divisor is 0public static long parseUnsignedLong(String s)
Returns the unsigned long
value represented by the given decimal string.
NumberFormatException
- if the string does not contain a valid unsigned long
valueNullPointerException
- if s
is null (in contrast to Long.parseLong(String)
)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:
0x
HexDigits
0X
HexDigits
#
HexDigits
0
OctalDigits
NumberFormatException
- if the string does not contain a valid unsigned long
valuepublic static long parseUnsignedLong(String s, int radix)
Returns the unsigned long
value represented by a string with the given radix.
s
- the string containing the unsigned long
representation to be parsed.radix
- the radix to use while parsing s
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)
)@CheckReturnValue public static String toString(long x)
Returns a string representation of x, where x is treated as unsigned.
@CheckReturnValue public static String toString(long x, int radix)
Returns a string representation of x
for the given radix, where x
is treated as unsigned.
x
- the value to convert to a string.radix
- the radix to use while working with x
IllegalArgumentException
- if radix
is not between Character.MIN_RADIX
and Character.MAX_RADIX
.