152 lines
6.0 KiB
OCaml
152 lines
6.0 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the GNU Library General Public License, with *)
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(* the special exception on linking described in file ../LICENSE. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(** 32-bit integers.
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This module provides operations on the type [int32]
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of signed 32-bit integers. Unlike the built-in [int] type,
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the type [int32] is guaranteed to be exactly 32-bit wide on all
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platforms. All arithmetic operations over [int32] are taken
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modulo 2{^32}.
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Performance notice: values of type [int32] occupy more memory
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space than values of type [int], and arithmetic operations on
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[int32] are generally slower than those on [int]. Use [int32]
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only when the application requires exact 32-bit arithmetic. *)
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val zero : int32
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(** The 32-bit integer 0. *)
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val one : int32
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(** The 32-bit integer 1. *)
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val minus_one : int32
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(** The 32-bit integer -1. *)
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external neg : int32 -> int32 = "%int32_neg"
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(** Unary negation. *)
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external add : int32 -> int32 -> int32 = "%int32_add"
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(** Addition. *)
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external sub : int32 -> int32 -> int32 = "%int32_sub"
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(** Subtraction. *)
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external mul : int32 -> int32 -> int32 = "%int32_mul"
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(** Multiplication. *)
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external div : int32 -> int32 -> int32 = "%int32_div"
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(** Integer division. Raise [Division_by_zero] if the second
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argument is zero. This division rounds the real quotient of
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its arguments towards zero, as specified for {!Pervasives.(/)}. *)
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external rem : int32 -> int32 -> int32 = "%int32_mod"
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(** Integer remainder. If [y] is not zero, the result
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of [Int32.rem x y] satisfies the following properties:
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[Int32.zero <= Int32.rem x y < Int32.abs y] and
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[x = Int32.add (Int32.mul (Int32.div x y) y) (Int32.rem x y)].
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If [y = 0], [Int32.rem x y] raises [Division_by_zero]. *)
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val succ : int32 -> int32
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(** Successor. [Int32.succ x] is [Int32.add x Int32.one]. *)
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val pred : int32 -> int32
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(** Predecessor. [Int32.pred x] is [Int32.sub x Int32.one]. *)
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val abs : int32 -> int32
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(** Return the absolute value of its argument. *)
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val max_int : int32
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(** The greatest representable 32-bit integer, 2{^31} - 1. *)
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val min_int : int32
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(** The smallest representable 32-bit integer, -2{^31}. *)
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external logand : int32 -> int32 -> int32 = "%int32_and"
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(** Bitwise logical and. *)
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external logor : int32 -> int32 -> int32 = "%int32_or"
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(** Bitwise logical or. *)
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external logxor : int32 -> int32 -> int32 = "%int32_xor"
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(** Bitwise logical exclusive or. *)
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val lognot : int32 -> int32
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(** Bitwise logical negation *)
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external shift_left : int32 -> int -> int32 = "%int32_lsl"
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(** [Int32.shift_left x y] shifts [x] to the left by [y] bits.
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The result is unspecified if [y < 0] or [y >= 32]. *)
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external shift_right : int32 -> int -> int32 = "%int32_asr"
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(** [Int32.shift_right x y] shifts [x] to the right by [y] bits.
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This is an arithmetic shift: the sign bit of [x] is replicated
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and inserted in the vacated bits.
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The result is unspecified if [y < 0] or [y >= 32]. *)
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external shift_right_logical : int32 -> int -> int32 = "%int32_lsr"
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(** [Int32.shift_right_logical x y] shifts [x] to the right by [y] bits.
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This is a logical shift: zeroes are inserted in the vacated bits
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regardless of the sign of [x].
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The result is unspecified if [y < 0] or [y >= 32]. *)
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external of_int : int -> int32 = "%int32_of_int"
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(** Convert the given integer (type [int]) to a 32-bit integer (type [int32]). *)
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external to_int : int32 -> int = "%int32_to_int"
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(** Convert the given 32-bit integer (type [int32]) to an
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integer (type [int]). On 32-bit platforms, the 32-bit integer
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is taken modulo 2{^31}, i.e. the high-order bit is lost
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during the conversion. On 64-bit platforms, the conversion
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is exact. *)
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external of_float : float -> int32 = "int32_of_float"
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(** Convert the given floating-point number to a 32-bit integer,
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discarding the fractional part (truncate towards 0).
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The result of the conversion is undefined if, after truncation,
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the number is outside the range \[{!Int32.min_int}, {!Int32.max_int}\]. *)
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external to_float : int32 -> float = "int32_to_float"
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(** Convert the given 32-bit integer to a floating-point number. *)
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external of_string : string -> int32 = "int32_of_string"
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(** Convert the given string to a 32-bit integer.
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The string is read in decimal (by default) or in hexadecimal,
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octal or binary if the string begins with [0x], [0o] or [0b]
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respectively.
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Raise [Failure "int_of_string"] if the given string is not
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a valid representation of an integer. *)
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val to_string : int32 -> string
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(** Return the string representation of its argument, in signed decimal. *)
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external format : string -> int32 -> string = "int32_format"
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(** [Int32.format fmt n] return the string representation of the
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32-bit integer [n] in the format specified by [fmt].
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[fmt] is a [Printf]-style format containing exactly
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one [%d], [%i], [%u], [%x], [%X] or [%o] conversion specification.
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This function is deprecated; use {!Printf.sprintf} with a [%lx] format
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instead. *)
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type t = int32
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(** An alias for the type of 32-bit integers. *)
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val compare: t -> t -> int
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(** The comparison function for 32-bit integers, with the same specification as
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{!Pervasives.compare}. Along with the type [t], this function [compare]
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allows the module [Int32] to be passed as argument to the functors
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{!Set.Make} and {!Map.Make}. *)
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