Module Base.Int32Source
An int of exactly 32 bits, regardless of the machine.
Side note: There's not much reason to want an int of at least 32 bits (i.e., 32 on 32-bit machines and 63 on 64-bit machines) because Int63 is basically just as efficient.
Overflow issues are not generally considered and explicitly handled. This may be more of an issue for 32-bit ints than 64-bit ints.
Int32.t is boxed on both 32-bit and 64-bit machines.
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 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.
Float division of integers.
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 Returns the absolute value of the argument. May be negative if the input is min_value.
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.
Same as shift_right_logical.
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.
A sub-module designed to be opened to make working with ints more convenient.
Conversion functions
Sourceval of_nativeint : nativeint -> t option Sourceval to_nativeint : t -> nativeint Sourceval of_int64 : int64 -> t option 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 of_nativeint_trunc : nativeint -> t Sourceval of_int64_trunc : int64 -> t Low-level float conversions
Sourceval bits_of_float : float -> t Rounds a regular 64-bit OCaml float to a 32-bit IEEE-754 "single" float, and returns its bit representation. We make no promises about the exact rounding behavior, or what happens in case of over- or underflow.
Sourceval float_of_bits : t -> float Creates a 32-bit IEEE-754 "single" float from the given bits, and converts it to a regular 64-bit OCaml float.
Byte swap operations
See Int's byte swap section for a description of Base's approach to exposing byte swap primitives.
When compiling for 64-bit machines, if signedness of the output value does not matter, use byteswap functions for int64, if possible, for better performance. As of writing, 32-bit byte swap operations on 64-bit machines have extra overhead for moving to 32-bit registers and sign-extending values when returning to 64-bit registers.
The x86 instruction sequence that demonstrates the overhead is in base/bench/bench_int.ml