(* This file is free software, part of containers. See file "license" for more details. *)

(** {1 Int32}

    Helpers for 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.

    @since 2.1 *)

include module type of struct include Int32 end

val ( + ) : t -> t -> t
(** Addition. *)

val ( - ) : t -> t -> t
(** Subtraction. *)

val ( ~- ) : t -> t
(** Unary negation. *)

val ( * ) : t -> t -> t
(** Multiplication. *)

val ( / ) : t -> t -> t
(** 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.(/)}. *)

val ( mod ) : t -> t -> t
(** [x mod y ] is the integer remainder.
    If [y <> zero], the result of [x mod y] satisfies the following property:
    [x = ((x / y) * y) + (x mod y)].
    If [y = 0], [x mod y] raises [Division_by_zero]. *)

val ( land ) : t -> t -> t
(** Bitwise logical and. *)

val ( lor ) : t -> t -> t
(** Bitwise logical or. *)

val ( lxor ) : t -> t -> t
(** Bitwise logical exclusive or. *)

val lnot : t -> t
(** Bitwise logical negation. *)

val ( lsl ) : t -> int -> t
(** [ x lsl y] shifts [x] to the left by [y] bits, filling in with zeroes.
    The result is unspecified if [y < 0] or [y >= 32]. *)

val ( lsr ) : t -> int -> t
(** [x lsr 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]. *)

val ( asr ) : t -> int -> t
(** [x asr 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]. *)

module Infix : sig
  val (+) : t -> t -> t
  val (-) : t -> t -> t
  val (~-) : t -> t
  val ( * ) : t -> t -> t
  val (/) : t -> t -> t
  val (mod) : t -> t -> t
  val (land) : t -> t -> t
  val (lor) : t -> t -> t
  val (lxor) : t -> t -> t
  val lnot : t -> t
  val (lsl) : t -> int -> t
  val (lsr) : t -> int -> t
  val (asr) : t -> int -> t
  val (=) : t -> t -> bool
  val (<>) : t -> t -> bool
  val (>) : t -> t -> bool
  val (>=) : t -> t -> bool
  val (<=) : t -> t -> bool
  val (<) : t -> t -> bool
end

val equal : t -> t -> bool
(** The equal function for 32-bit integers.
    Like {!Pervasives.(=) x y)}. *)

val hash : t -> int
(** Like {!Pervasives.abs (to_int x)}. *)

(** {2 Conversion} *)

val to_int : t -> 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. *)

val of_int : int -> t
(** Alias to {!Int32.of_int}. *)

val to_float : t -> float
(** Convert the given 32-bit integer to a floating-point number. *)

val of_float : float -> t
(** Alias to {!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 \[{!CCInt32.min_int}, {!CCInt32.max_int}\]. *)

val to_string : t -> string
(** Return the string representation of its argument, in signed decimal. *)

val of_string_exn : string -> t
(** Alias to {!Int32.of_string}.
    Convert the given string to a 32-bit integer.
    The string is read in decimal (by default, or if the string
    begins with [0u]) or in hexadecimal, octal or binary if the
    string begins with [0x], [0o] or [0b] respectively.

    The [0u] prefix reads the input as an unsigned integer in the range
    [[0, 2*CCInt32.max_int+1]]. If the input exceeds {!CCInt32.max_int}
    it is converted to the signed integer
    [CCInt32.min_int + input - CCInt32.max_int - 1].

    The [_] (underscore) character can appear anywhere in the string
    and is ignored.
    Raise [Failure "Int32.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 of_string : string -> t option
(** Safe version of {!of_string_exn}.
    Like {!of_string_exn}, but return [None] instead of raising. *)

val of_string_opt : string -> t option
(** Alias to {!of_string}. *)