ocaml/stdlib/nativeint.mli

186 lines
7.3 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* 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. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(** Processor-native integers.
This module provides operations on the type [nativeint] of
signed 32-bit integers (on 32-bit platforms) or
signed 64-bit integers (on 64-bit platforms).
This integer type has exactly the same width as that of a [long]
integer type in the C compiler. All arithmetic operations over
[nativeint] are taken modulo 2{^32} or 2{^64} depending
on the word size of the architecture.
Performance notice: values of type [nativeint] occupy more memory
space than values of type [int], and arithmetic operations on
[nativeint] are generally slower than those on [int]. Use [nativeint]
only when the application requires the extra bit of precision
over the [int] type.
*)
val zero : nativeint
(** The native integer 0.*)
val one : nativeint
(** The native integer 1.*)
val minus_one : nativeint
(** The native integer -1.*)
external neg : nativeint -> nativeint = "%nativeint_neg"
(** Unary negation. *)
external add : nativeint -> nativeint -> nativeint = "%nativeint_add"
(** Addition. *)
external sub : nativeint -> nativeint -> nativeint = "%nativeint_sub"
(** Subtraction. *)
external mul : nativeint -> nativeint -> nativeint = "%nativeint_mul"
(** Multiplication. *)
external div : nativeint -> nativeint -> nativeint = "%nativeint_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 : nativeint -> nativeint -> nativeint = "%nativeint_mod"
(** Integer remainder. If [y] is not zero, the result
of [Nativeint.rem x y] satisfies the following properties:
[Nativeint.zero <= Nativeint.rem x y < Nativeint.abs y] and
[x = Nativeint.add (Nativeint.mul (Nativeint.div x y) y) (Nativeint.rem x y)].
If [y = 0], [Nativeint.rem x y] raises [Division_by_zero]. *)
val succ : nativeint -> nativeint
(** Successor.
[Nativeint.succ x] is [Nativeint.add x Nativeint.one]. *)
val pred : nativeint -> nativeint
(** Predecessor.
[Nativeint.pred x] is [Nativeint.sub x Nativeint.one]. *)
val abs : nativeint -> nativeint
(** Return the absolute value of its argument. *)
val size : int
(** The size in bits of a native integer. This is equal to [32]
on a 32-bit platform and to [64] on a 64-bit platform. *)
val max_int : nativeint
(** The greatest representable native integer,
either 2{^31} - 1 on a 32-bit platform,
or 2{^63} - 1 on a 64-bit platform. *)
val min_int : nativeint
(** The greatest representable native integer,
either -2{^31} on a 32-bit platform,
or -2{^63} on a 64-bit platform. *)
external logand : nativeint -> nativeint -> nativeint = "%nativeint_and"
(** Bitwise logical and. *)
external logor : nativeint -> nativeint -> nativeint = "%nativeint_or"
(** Bitwise logical or. *)
external logxor : nativeint -> nativeint -> nativeint = "%nativeint_xor"
(** Bitwise logical exclusive or. *)
val lognot : nativeint -> nativeint
(** Bitwise logical negation *)
external shift_left : nativeint -> int -> nativeint = "%nativeint_lsl"
(** [Nativeint.shift_left x y] shifts [x] to the left by [y] bits.
The result is unspecified if [y < 0] or [y >= bitsize],
where [bitsize] is [32] on a 32-bit platform and
[64] on a 64-bit platform. *)
external shift_right : nativeint -> int -> nativeint = "%nativeint_asr"
(** [Nativeint.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 >= bitsize]. *)
external shift_right_logical :
nativeint -> int -> nativeint = "%nativeint_lsr"
(** [Nativeint.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 >= bitsize]. *)
external of_int : int -> nativeint = "%nativeint_of_int"
(** Convert the given integer (type [int]) to a native integer
(type [nativeint]). *)
external to_int : nativeint -> int = "%nativeint_to_int"
(** Convert the given native integer (type [nativeint]) to an
integer (type [int]). The high-order bit is lost during
the conversion. *)
external of_float : float -> nativeint = "nativeint_of_float"
(** Convert the given floating-point number to a native integer,
discarding the fractional part (truncate towards 0).
The result of the conversion is undefined if, after truncation,
the number is outside the range
\[{!Nativeint.min_int}, {!Nativeint.max_int}\]. *)
external to_float : nativeint -> float = "nativeint_to_float"
(** Convert the given native integer to a floating-point number. *)
external of_int32 : int32 -> nativeint = "%nativeint_of_int32"
(** Convert the given 32-bit integer (type [int32])
to a native integer. *)
external to_int32 : nativeint -> int32 = "%nativeint_to_int32"
(** Convert the given native integer to a
32-bit integer (type [int32]). On 64-bit platforms,
the 64-bit native integer is taken modulo 2{^32},
i.e. the top 32 bits are lost. On 32-bit platforms,
the conversion is exact. *)
external of_string : string -> nativeint = "nativeint_of_string"
(** Convert the given string to a native 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. *)
val to_string : nativeint -> string
(** Return the string representation of its argument, in decimal. *)
type t = nativeint
(** An alias for the type of native integers. *)
val compare: t -> t -> int
(** The comparison function for native integers, with the same specification as
{!Pervasives.compare}. Along with the type [t], this function [compare]
allows the module [Nativeint] to be passed as argument to the functors
{!Set.Make} and {!Map.Make}. *)
(**/**)
(** {6 Deprecated functions} *)
external format : string -> nativeint -> string = "nativeint_format"
(** [Nativeint.format fmt n] return the string representation of the
native integer [n] in the format specified by [fmt].
[fmt] is a [Printf]-style format consisting of exactly
one [%d], [%i], [%u], [%x], [%X] or [%o] conversion specification.
This function is deprecated; use {!Printf.sprintf} with a [%nx] format
instead. *)