Module Base.Int
Source
include Identifiable.S with type t := t
include Comparable.S with type t := t
include Comparisons.S with type t := t
compare t1 t2
returns 0 if t1
is equal to t2
, a negative integer if t1
is less than t2
, and a positive integer if t1
is greater than t2
.
ascending
is identical to compare
. descending x y = ascending y x
. These are intended to be mnemonic when used like List.sort ~compare:ascending
and List.sort ~cmp:descending
, since they cause the list to be sorted in ascending or descending order, respectively.
Sourceval between : t -> low:t -> high:t -> bool
between t ~low ~high
means low <= t <= high
clamp_exn t ~min ~max
returns t'
, the closest value to t
such that between t' ~low:min ~high:max
is true.
Raises if not (min <= max)
.
include Comparable.With_zero with type t := t
Sourceval is_non_negative : t -> bool
Sourceval is_non_positive : t -> bool
Returns Neg
, Zero
, or Pos
in a way consistent with the above functions.
Sourceval compare__local : t -> t -> int
Sourceval of_string_opt : string -> t option
Sourceval to_string_hum : ?delimiter:char -> t -> string
delimiter
is an underscore by default.
Infix operators and constants
Negation
There are two pairs of integer division and remainder functions, /%
and %
, and /
and rem
. They both satisfy the same equation relating the quotient and the remainder:
x = (x /% y) * y + (x % y);
x = (x / y) * y + (rem x y);
The functions return the same values if x
and y
are positive. They all raise if y = 0
.
The functions differ if x < 0
or y < 0
.
If y < 0
, then %
and /%
raise, whereas /
and rem
do not.
x % y
always returns a value between 0 and y - 1
, even when x < 0
. On the other hand, rem x y
returns a negative value if and only if x < 0
; that value satisfies abs (rem x y) <= abs y - 1
.
Other common functions
round
rounds an int to a multiple of a given to_multiple_of
argument, according to a direction dir
, with default dir
being `Nearest
. round
will raise if to_multiple_of <= 0
. If the result overflows (too far positive or too far negative), round
returns an incorrect result.
| `Down | rounds toward Int.neg_infinity |
| `Up | rounds toward Int.infinity |
| `Nearest | rounds to the nearest multiple, or `Up in case of a tie |
| `Zero | rounds toward zero |
Here are some examples for round ~to_multiple_of:10
for each direction:
| `Down | {10 .. 19} --> 10 | { 0 ... 9} --> 0 | {-10 ... -1} --> -10 |
| `Up | { 1 .. 10} --> 10 | {-9 ... 0} --> 0 | {-19 .. -10} --> -10 |
| `Zero | {10 .. 19} --> 10 | {-9 ... 9} --> 0 | {-19 .. -10} --> -10 |
| `Nearest | { 5 .. 14} --> 10 | {-5 ... 4} --> 0 | {-15 ... -6} --> -10 |
For convenience and performance, there are variants of round
with dir
hard-coded. If you are writing performance-critical code you should use these.
Sourceval round :
?dir:[ `Zero | `Nearest | `Up | `Down ] ->
t ->
to_multiple_of:t ->
t
Sourceval round_towards_zero : t -> to_multiple_of:t -> t
Sourceval round_down : t -> to_multiple_of:t -> t
Sourceval round_up : t -> to_multiple_of:t -> t
Sourceval round_nearest : t -> to_multiple_of:t -> t
Successor and predecessor functions
Exponentiation
pow base exponent
returns base
raised to the power of exponent
. It is OK if base <= 0
. pow
raises if exponent < 0
, or an integer overflow would occur.
Bit-wise logical operations
These are identical to land
, lor
, etc. except they're not infix and have different names.
Returns the number of 1 bits in the binary representation of the input.
Bit-shifting operations
The results are unspecified for negative shifts and shifts >= num_bits
.
Shifts left, filling in with zeroes.
Shifts right, preserving the sign of the input.
Increment and decrement functions for integer references
Sourceval of_int32_exn : int32 -> t
Sourceval to_int32_exn : t -> int32
Sourceval of_int64_exn : int64 -> t
Sourceval of_nativeint_exn : nativeint -> t
Sourceval to_nativeint_exn : t -> nativeint
Sourceval of_float_unchecked : float -> t
of_float_unchecked
truncates the given floating point number to an integer, rounding towards zero. The result is unspecified if the argument is nan or falls outside the range of representable integers.
The number of bits available in this integer type. Note that the integer representations are signed.
The largest representable integer.
The smallest representable integer.
Sourceval shift_right_logical : t -> int -> t
Shifts right, filling in with zeroes, which will not preserve the sign of the input.
ceil_pow2 x
returns the smallest power of 2 that is greater than or equal to x
. The implementation may only be called for x > 0
. Example: ceil_pow2 17 = 32
floor_pow2 x
returns the largest power of 2 that is less than or equal to x
. The implementation may only be called for x > 0
. Example: floor_pow2 17 = 16
ceil_log2 x
returns the ceiling of log-base-2 of x
, and raises if x <= 0
.
floor_log2 x
returns the floor of log-base-2 of x
, and raises if x <= 0
.
is_pow2 x
returns true iff x
is a power of 2. is_pow2
raises if x <= 0
.
Returns the number of leading zeros in the binary representation of the input, as an integer between 0 and one less than num_bits
.
The results are unspecified for t = 0
.
Returns the number of trailing zeros in the binary representation of the input, as an integer between 0 and one less than num_bits
.
The results are unspecified for t = 0
.
max_value_30_bits = 2^30 - 1
. It is useful for writing tests that work on both 64-bit and 32-bit platforms.
Conversion functions
Sourceval of_int32 : int32 -> t option
Sourceval to_int32 : t -> int32 option
Sourceval of_int64 : int64 -> t option
Sourceval of_nativeint : nativeint -> t option
Sourceval to_nativeint : t -> nativeint
Truncating conversions
These functions return the least-significant bits of the input. In cases where optional conversions return Some x
, truncating conversions return x
.
Sourceval to_int32_trunc : t -> int32
Sourceval of_int32_trunc : int32 -> t
Sourceval of_int64_trunc : int64 -> t
Sourceval of_nativeint_trunc : nativeint -> t
Byte swap operations
Byte swap operations reverse the order of bytes in an integer. For example, Int32.bswap32
reorders the bottom 32 bits (or 4 bytes), turning 0x1122_3344
to 0x4433_2211
. Byte swap functions exposed by Base use OCaml primitives to generate assembly instructions to perform the relevant byte swaps.
For a more extensive list of byteswap functions, see Int32
and Int64
.
Sourceval bswap16 : int -> int
Byte swaps bottom 16 bits (2 bytes). The values of the remaining bytes are undefined.
Module types specifying integer operations.
OCaml's native integer type.