ocaml/otherlibs/num/big_int.mli

192 lines
8.8 KiB
OCaml

(***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* Valerie Menissier-Morain, 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. *)
(* *)
(***********************************************************************)
(** Operations on arbitrary-precision integers.
Big integers (type [big_int]) are signed integers of arbitrary size.
*)
open Nat
type big_int
(** The type of big integers. *)
val zero_big_int : big_int
(** The big integer [0]. *)
val unit_big_int : big_int
(** The big integer [1]. *)
(** {6 Arithmetic operations} *)
val minus_big_int : big_int -> big_int
(** Unary negation. *)
val abs_big_int : big_int -> big_int
(** Absolute value. *)
val add_big_int : big_int -> big_int -> big_int
(** Addition. *)
val succ_big_int : big_int -> big_int
(** Successor (add 1). *)
val add_int_big_int : int -> big_int -> big_int
(** Addition of a small integer to a big integer. *)
val sub_big_int : big_int -> big_int -> big_int
(** Subtraction. *)
val pred_big_int : big_int -> big_int
(** Predecessor (subtract 1). *)
val mult_big_int : big_int -> big_int -> big_int
(** Multiplication of two big integers. *)
val mult_int_big_int : int -> big_int -> big_int
(** Multiplication of a big integer by a small integer *)
val square_big_int: big_int -> big_int
(** Return the square of the given big integer *)
val sqrt_big_int: big_int -> big_int
(** [sqrt_big_int a] returns the integer square root of [a],
that is, the largest big integer [r] such that [r * r <= a].
Raise [Invalid_argument] if [a] is negative. *)
val quomod_big_int : big_int -> big_int -> big_int * big_int
(** Euclidean division of two big integers.
The first part of the result is the quotient,
the second part is the remainder.
Writing [(q,r) = quomod_big_int a b], we have
[a = q * b + r] and [0 <= r < |b|].
Raise [Division_by_zero] if the divisor is zero. *)
val div_big_int : big_int -> big_int -> big_int
(** Euclidean quotient of two big integers.
This is the first result [q] of [quomod_big_int] (see above). *)
val mod_big_int : big_int -> big_int -> big_int
(** Euclidean modulus of two big integers.
This is the second result [r] of [quomod_big_int] (see above). *)
val gcd_big_int : big_int -> big_int -> big_int
(** Greatest common divisor of two big integers. *)
val power_int_positive_int: int -> int -> big_int
val power_big_int_positive_int: big_int -> int -> big_int
val power_int_positive_big_int: int -> big_int -> big_int
val power_big_int_positive_big_int: big_int -> big_int -> big_int
(** Exponentiation functions. Return the big integer
representing the first argument [a] raised to the power [b]
(the second argument). Depending
on the function, [a] and [b] can be either small integers
or big integers. Raise [Invalid_argument] if [b] is negative. *)
(** {6 Comparisons and tests} *)
val sign_big_int : big_int -> int
(** Return [0] if the given big integer is zero,
[1] if it is positive, and [-1] if it is negative. *)
val compare_big_int : big_int -> big_int -> int
(** [compare_big_int a b] returns [0] if [a] and [b] are equal,
[1] if [a] is greater than [b], and [-1] if [a] is smaller
than [b]. *)
val eq_big_int : big_int -> big_int -> bool
val le_big_int : big_int -> big_int -> bool
val ge_big_int : big_int -> big_int -> bool
val lt_big_int : big_int -> big_int -> bool
val gt_big_int : big_int -> big_int -> bool
(** Usual boolean comparisons between two big integers. *)
val max_big_int : big_int -> big_int -> big_int
(** Return the greater of its two arguments. *)
val min_big_int : big_int -> big_int -> big_int
(** Return the smaller of its two arguments. *)
val num_digits_big_int : big_int -> int
(** Return the number of machine words used to store the
given big integer. *)
(** {6 Conversions to and from strings} *)
val string_of_big_int : big_int -> string
(** Return the string representation of the given big integer,
in decimal (base 10). *)
val big_int_of_string : string -> big_int
(** Convert a string to a big integer, in decimal.
The string consists of an optional [-] or [+] sign,
followed by one or several decimal digits. *)
(** {6 Conversions to and from other numerical types} *)
val big_int_of_int : int -> big_int
(** Convert a small integer to a big integer. *)
val is_int_big_int : big_int -> bool
(** Test whether the given big integer is small enough to
be representable as a small integer (type [int])
without loss of precision. On a 32-bit platform,
[is_int_big_int a] returns [true] if and only if
[a] is between 2{^30} and 2{^30}-1. On a 64-bit platform,
[is_int_big_int a] returns [true] if and only if
[a] is between -2{^62} and 2{^62}-1. *)
val int_of_big_int : big_int -> int
(** Convert a big integer to a small integer (type [int]).
Raises [Failure "int_of_big_int"] if the big integer
is not representable as a small integer. *)
val big_int_of_int32 : int32 -> big_int
(** Convert a 32-bit integer to a big integer. *)
val big_int_of_nativeint : nativeint -> big_int
(** Convert a native integer to a big integer. *)
val big_int_of_int64 : int64 -> big_int
(** Convert a 64-bit integer to a big integer. *)
val int32_of_big_int : big_int -> int32
(** Convert a big integer to a 32-bit integer.
Raises [Failure] if the big integer is outside the
range [[-2{^31}, 2{^31}-1]]. *)
val nativeint_of_big_int : big_int -> nativeint
(** Convert a big integer to a native integer.
Raises [Failure] if the big integer is outside the
range [[Nativeint.min_int, Nativeint.max_int]]. *)
val int64_of_big_int : big_int -> int64
(** Convert a big integer to a 64-bit integer.
Raises [Failure] if the big integer is outside the
range [[-2{^63}, 2{^63}-1]]. *)
val float_of_big_int : big_int -> float
(** Returns a floating-point number approximating the
given big integer. *)
(** {6 Bit-oriented operations} *)
val and_big_int : big_int -> big_int -> big_int
(** Bitwise logical 'and'.
The arguments must be positive or zero. *)
val or_big_int : big_int -> big_int -> big_int
(** Bitwise logical 'or'.
The arguments must be positive or zero. *)
val xor_big_int : big_int -> big_int -> big_int
(** Bitwise logical 'exclusive or'.
The arguments must be positive or zero. *)
val shift_left_big_int : big_int -> int -> big_int
(** [shift_left_big_int b n] returns [b] shifted left by [n] bits.
Equivalent to multiplication by [2^n]. *)
val shift_right_big_int : big_int -> int -> big_int
(** [shift_right_big_int b n] returns [b] shifted right by [n] bits.
Equivalent to division by [2^n] with the result being
rounded towards minus infinity. *)
val shift_right_towards_zero_big_int : big_int -> int -> big_int
(** [shift_right_towards_zero_big_int b n] returns [b] shifted
right by [n] bits. The shift is performed on the absolute
value of [b], and the result has the same sign as [b].
Equivalent to division by [2^n] with the result being
rounded towards zero. *)
val extract_big_int : big_int -> int -> int -> big_int
(** [extract_big_int bi ofs n] returns a nonnegative number
corresponding to bits [ofs] to [ofs + n - 1] of the
binary representation of [bi]. If [bi] is negative,
a two's complement representation is used. *)
(**/**)
(** {6 For internal use} *)
val nat_of_big_int : big_int -> nat
val big_int_of_nat : nat -> big_int
val base_power_big_int: int -> int -> big_int -> big_int
val sys_big_int_of_string: string -> int -> int -> big_int
val round_futur_last_digit : bytes -> int -> int -> bool
val approx_big_int: int -> big_int -> string