ocaml/stdlib/int32.mli

163 lines
6.4 KiB
OCaml

(***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License, with *)
(* the special exception on linking described in file ../LICENSE. *)
(* *)
(***********************************************************************)
(** 32-bit integers.
This module provides operations on the type [int32]
of signed 32-bit integers. Unlike the built-in [int] type,
the type [int32] is guaranteed to be exactly 32-bit wide on all
platforms. All arithmetic operations over [int32] are taken
modulo 2{^32}.
Performance notice: values of type [int32] occupy more memory
space than values of type [int], and arithmetic operations on
[int32] are generally slower than those on [int]. Use [int32]
only when the application requires exact 32-bit arithmetic. *)
val zero : int32
(** The 32-bit integer 0. *)
val one : int32
(** The 32-bit integer 1. *)
val minus_one : int32
(** The 32-bit integer -1. *)
external neg : int32 -> int32 = "%int32_neg"
(** Unary negation. *)
external add : int32 -> int32 -> int32 = "%int32_add"
(** Addition. *)
external sub : int32 -> int32 -> int32 = "%int32_sub"
(** Subtraction. *)
external mul : int32 -> int32 -> int32 = "%int32_mul"
(** Multiplication. *)
external div : int32 -> int32 -> int32 = "%int32_div"
(** Integer division. Raise [Division_by_zero] if the second
argument is zero. This division rounds the real quotient of
its arguments towards zero, as specified for {!Pervasives.(/)}. *)
external rem : int32 -> int32 -> int32 = "%int32_mod"
(** Integer remainder. If [y] is not zero, the result
of [Int32.rem x y] satisfies the following property:
[x = Int32.add (Int32.mul (Int32.div x y) y) (Int32.rem x y)].
If [y = 0], [Int32.rem x y] raises [Division_by_zero]. *)
val succ : int32 -> int32
(** Successor. [Int32.succ x] is [Int32.add x Int32.one]. *)
val pred : int32 -> int32
(** Predecessor. [Int32.pred x] is [Int32.sub x Int32.one]. *)
val abs : int32 -> int32
(** Return the absolute value of its argument. *)
val max_int : int32
(** The greatest representable 32-bit integer, 2{^31} - 1. *)
val min_int : int32
(** The smallest representable 32-bit integer, -2{^31}. *)
external logand : int32 -> int32 -> int32 = "%int32_and"
(** Bitwise logical and. *)
external logor : int32 -> int32 -> int32 = "%int32_or"
(** Bitwise logical or. *)
external logxor : int32 -> int32 -> int32 = "%int32_xor"
(** Bitwise logical exclusive or. *)
val lognot : int32 -> int32
(** Bitwise logical negation *)
external shift_left : int32 -> int -> int32 = "%int32_lsl"
(** [Int32.shift_left x y] shifts [x] to the left by [y] bits.
The result is unspecified if [y < 0] or [y >= 32]. *)
external shift_right : int32 -> int -> int32 = "%int32_asr"
(** [Int32.shift_right x y] shifts [x] to the right by [y] bits.
This is an arithmetic shift: the sign bit of [x] is replicated
and inserted in the vacated bits.
The result is unspecified if [y < 0] or [y >= 32]. *)
external shift_right_logical : int32 -> int -> int32 = "%int32_lsr"
(** [Int32.shift_right_logical x y] shifts [x] to the right by [y] bits.
This is a logical shift: zeroes are inserted in the vacated bits
regardless of the sign of [x].
The result is unspecified if [y < 0] or [y >= 32]. *)
external of_int : int -> int32 = "%int32_of_int"
(** Convert the given integer (type [int]) to a 32-bit integer
(type [int32]). *)
external to_int : int32 -> int = "%int32_to_int"
(** Convert the given 32-bit integer (type [int32]) to an
integer (type [int]). On 32-bit platforms, the 32-bit integer
is taken modulo 2{^31}, i.e. the high-order bit is lost
during the conversion. On 64-bit platforms, the conversion
is exact. *)
external of_float : float -> int32 = "caml_int32_of_float"
(** Convert the given floating-point number to a 32-bit integer,
discarding the fractional part (truncate towards 0).
The result of the conversion is undefined if, after truncation,
the number is outside the range \[{!Int32.min_int}, {!Int32.max_int}\]. *)
external to_float : int32 -> float = "caml_int32_to_float"
(** Convert the given 32-bit integer to a floating-point number. *)
external of_string : string -> int32 = "caml_int32_of_string"
(** Convert the given string to a 32-bit integer.
The string is read in decimal (by default) or in hexadecimal,
octal or binary if the string begins with [0x], [0o] or [0b]
respectively.
Raise [Failure "int_of_string"] if the given string is not
a valid representation of an integer, or if the integer represented
exceeds the range of integers representable in type [int32]. *)
val to_string : int32 -> string
(** Return the string representation of its argument, in signed decimal. *)
external bits_of_float : float -> int32 = "caml_int32_bits_of_float"
(** Return the internal representation of the given float according
to the IEEE 754 floating-point ``single format'' bit layout.
Bit 31 of the result represents the sign of the float;
bits 30 to 23 represent the (biased) exponent; bits 22 to 0
represent the mantissa. *)
external float_of_bits : int32 -> float = "caml_int32_float_of_bits"
(** Return the floating-point number whose internal representation,
according to the IEEE 754 floating-point ``single format'' bit layout,
is the given [int32]. *)
type t = int32
(** An alias for the type of 32-bit integers. *)
val compare: t -> t -> int
(** The comparison function for 32-bit integers, with the same specification as
{!Pervasives.compare}. Along with the type [t], this function [compare]
allows the module [Int32] to be passed as argument to the functors
{!Set.Make} and {!Map.Make}. *)
(**/**)
(** {6 Deprecated functions} *)
external format : string -> int32 -> string = "caml_int32_format"
(** Do not use this deprecated function. Instead,
used {!Printf.sprintf} with a [%l...] format. *)