package base

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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.

Sourcetype t = int32
include Sexpable.S with type t := t
include Floatable.S with type t := t
Sourceval of_float : float -> t
Sourceval to_float : t -> float
include Intable.S with type t := t
Sourceval of_int_exn : int -> t
Sourceval to_int_exn : t -> int
include Identifiable.S with type t := t
Sourceval hash_fold_t : Hash.state -> t -> Hash.state
Sourceval hash : t -> Hash.hash_value
include Sexpable.S with type t := t
Sourceval t_of_sexp : Sexplib0.Sexp.t -> t
Sourceval sexp_of_t : t -> Sexplib0.Sexp.t
include Stringable.S with type t := t
Sourceval of_string : string -> t
Sourceval to_string : t -> string
include Comparable.S with type t := t
include Comparisons.S with type t := t
include Comparisons.Infix with type t := t
Sourceval (>=) : t -> t -> bool
Sourceval (<=) : t -> t -> bool
Sourceval (=) : t -> t -> bool
Sourceval (>) : t -> t -> bool
Sourceval (<) : t -> t -> bool
Sourceval (<>) : t -> t -> bool
Sourceval equal : t -> t -> bool
Sourceval compare : t -> t -> int

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.

Sourceval min : t -> t -> t
Sourceval max : t -> t -> t
Sourceval ascending : t -> t -> int

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 descending : t -> t -> int
Sourceval between : t -> low:t -> high:t -> bool

between t ~low ~high means low <= t <= high

Sourceval clamp_exn : t -> min:t -> max:t -> t

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).

Sourceval clamp : t -> min:t -> max:t -> t Or_error.t
include Comparator.S with type t := t
Sourcetype comparator_witness
Sourceval validate_lbound : min:t Maybe_bound.t -> t Validate.check
Sourceval validate_ubound : max:t Maybe_bound.t -> t Validate.check
Sourceval validate_bound : min:t Maybe_bound.t -> max:t Maybe_bound.t -> t Validate.check
include Pretty_printer.S with type t := t
Sourceval pp : Formatter.t -> t -> unit
include Comparable.With_zero with type t := t
Sourceval validate_positive : t Validate.check
Sourceval validate_non_negative : t Validate.check
Sourceval validate_negative : t Validate.check
Sourceval validate_non_positive : t Validate.check
Sourceval is_positive : t -> bool
Sourceval is_non_negative : t -> bool
Sourceval is_negative : t -> bool
Sourceval is_non_positive : t -> bool
Sourceval sign : t -> Base__.Sign0.t

Returns Neg, Zero, or Pos in a way consistent with the above functions.

include Invariant.S with type t := t
Sourceval invariant : t -> unit
Sourcemodule Hex : sig ... end
Sourceval to_string_hum : ?delimiter:char -> t -> string

delimiter is an underscore by default.

Infix operators and constants

Sourceval zero : t
Sourceval one : t
Sourceval minus_one : t
Sourceval (+) : t -> t -> t
Sourceval (-) : t -> t -> t
Sourceval (*) : t -> t -> t
Sourceval (**) : t -> t -> t

Integer exponentiation

Negation

Sourceval neg : t -> t
Sourceval (~-) : t -> t

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.

Sourceval (/%) : t -> t -> t
Sourceval (%) : t -> t -> t
Sourceval (/) : t -> t -> t
Sourceval rem : t -> t -> t
Sourceval (//) : t -> t -> float

Float division of integers.

Sourceval (land) : t -> t -> t

Same as bit_and.

Sourceval (lor) : t -> t -> t

Same as bit_or.

Sourceval (lxor) : t -> t -> t

Same as bit_xor.

Sourceval lnot : t -> t

Same as bit_not.

Sourceval (lsl) : t -> int -> t

Same as shift_left.

Sourceval (asr) : t -> int -> t

Same as shift_right.

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
Sourceval abs : t -> t

Returns the absolute value of the argument. May be negative if the input is min_value.

Successor and predecessor functions

Sourceval succ : t -> t
Sourceval pred : t -> t

Exponentiation

Sourceval pow : t -> t -> t

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

Sourceval bit_and : t -> t -> t

These are identical to land, lor, etc. except they're not infix and have different names.

Sourceval bit_or : t -> t -> t
Sourceval bit_xor : t -> t -> t
Sourceval bit_not : t -> t
Sourceval popcount : t -> int

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.

Sourceval shift_left : t -> int -> t

Shifts left, filling in with zeroes.

Sourceval shift_right : t -> int -> t

Shifts right, preserving the sign of the input.

Increment and decrement functions for integer references

Sourceval decr : t Caml.ref -> unit
Sourceval incr : t Caml.ref -> unit
Sourceval of_int32_exn : int32 -> t
Sourceval to_int32_exn : t -> int32
Sourceval of_int64_exn : int64 -> t
Sourceval to_int64 : t -> int64
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.

Sourceval num_bits : int

The number of bits available in this integer type. Note that the integer representations are signed.

Sourceval max_value : t

The largest representable integer.

Sourceval min_value : t

The smallest representable integer.

Sourceval (lsr) : t -> int -> t

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.

Sourceval ceil_pow2 : t -> t

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

Sourceval floor_pow2 : t -> t

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

Sourceval ceil_log2 : t -> int

ceil_log2 x returns the ceiling of log-base-2 of x, and raises if x <= 0.

Sourceval floor_log2 : t -> int

floor_log2 x returns the floor of log-base-2 of x, and raises if x <= 0.

Sourceval is_pow2 : t -> bool

is_pow2 x returns true iff x is a power of 2. is_pow2 raises if x <= 0.

Sourceval clz : t -> int

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.

Sourceval ctz : t -> int

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.

Sourcemodule O : sig ... end

A sub-module designed to be opened to make working with ints more convenient.

Conversion functions

Sourceval of_int : int -> t option
Sourceval to_int : t -> int option
Sourceval of_int32 : int32 -> t
Sourceval to_int32 : t -> int32
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_int_trunc : int -> t
Sourceval to_int_trunc : t -> int
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

Sourceval bswap16 : t -> t
Sourceval bswap32 : t -> t