Nativeint(3)

NAME
Nativeint - Processor-native integers.

Module
Module Nativeint

Documentation

Module Nativeint
 : sig end

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 pointer 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.

Literals for native integers are suffixed by n:
         let zero: nativeint = 0n
         let one: nativeint = 1n
         let m_one: nativeint = -1n

val zero : nativeint

The native integer 0.

val one : nativeint

The native integer 1.

val minus_one : nativeint

The native integer -1.

val neg : nativeint -> nativeint

Unary negation.

val add : nativeint -> nativeint -> nativeint

Addition.

val sub : nativeint -> nativeint -> nativeint

Subtraction.

val mul : nativeint -> nativeint -> nativeint

Multiplication.

val div : nativeint -> nativeint -> nativeint

Integer division. This division rounds the real quotient of its arguments towards zero, as specified for (/) .

Raises Division_by_zero if the second argument is zero.

val unsigned_div : nativeint -> nativeint -> nativeint

Same as Nativeint.div , except that arguments and result are interpreted as unsigned native integers.

Since 4.08

val rem : nativeint -> nativeint -> nativeint

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 unsigned_rem : nativeint -> nativeint -> nativeint

Same as Nativeint.rem , except that arguments and result are interpreted as unsigned native integers.

Since 4.08

val fdiv : nativeint -> nativeint -> nativeint

Floor division. fdiv x y is the real quotient x / y rounded down to an integer. We have fdiv x y <= div x y <= cdiv x y and cdiv x y - fdiv x y <= 1 .

Since 5.5

Raises Division_by_zero if the second argument is 0.

val cdiv : nativeint -> nativeint -> nativeint

Ceil division. cdiv x y is the real quotient x / y rounded up to an integer. We have fdiv x y <= div x y <= cdiv x y and cdiv x y - fdiv x y <= 1 .

Since 5.5

Raises Division_by_zero if the second argument is 0.

val ediv : nativeint -> nativeint -> nativeint

Euclidean division. ediv x y is the real quotient x / y rounded down to an integer if y > 0 and rounded up to an integer if y < 0 . The remainder erem x y = x - ediv x y * y is always non-negative. Moreover, ediv x (-y) = - ediv x y .

Since 5.5

Raises Division_by_zero if the second argument is 0.

val erem : nativeint -> nativeint -> nativeint

Euclidean remainder. If y is not zero, we have x = ediv x y * y + erem x y and 0 <= erem x y <= abs y - 1 . The result of erem x y is always non-negative, unlike the result of rem x y , which has the sign of x .

Since 5.5

Raises Division_by_zero if the second argument is 0.

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

abs x is the absolute value of x . On min_int this is min_int itself and thus remains negative.

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 smallest representable native integer, either -2^31 on a 32-bit platform, or -2^63 on a 64-bit platform.

val logand : nativeint -> nativeint -> nativeint

Bitwise logical and.

val logor : nativeint -> nativeint -> nativeint

Bitwise logical or.

val logxor : nativeint -> nativeint -> nativeint

Bitwise logical exclusive or.

val lognot : nativeint -> nativeint

Bitwise logical negation.

val shift_left : nativeint -> int -> nativeint

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.

val shift_right : nativeint -> int -> nativeint

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 .

val shift_right_logical : nativeint -> int -> nativeint

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 .

val of_int : int -> nativeint

Convert the given integer (type int ) to a native integer (type nativeint ).

val to_int : nativeint -> int

Convert the given native integer (type nativeint ) to an integer (type int ). The high-order bit is lost during the conversion.

val unsigned_to_int : nativeint -> int option

Same as Nativeint.to_int , but interprets the argument as an unsigned integer. Returns None if the unsigned value of the argument cannot fit into an int .

Since 4.08

val of_float : float -> nativeint

Convert the given floating-point number to a native integer, discarding the fractional part (truncate towards 0). If the truncated floating-point number is outside the range [ Nativeint.min_int , Nativeint.max_int ], no exception is raised, and an unspecified, platform-dependent integer is returned.

val to_float : nativeint -> float

Convert the given native integer to a floating-point number.

val of_int32 : int32 -> nativeint

Convert the given 32-bit integer (type int32 ) to a native integer.

val to_int32 : nativeint -> 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.

val of_string : string -> nativeint

Convert the given string to a native 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*Nativeint.max_int+1] . If the input exceeds Nativeint.max_int it is converted to the signed integer Int64.min_int + input - Nativeint.max_int - 1 .

Raises Failure 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 nativeint .

val of_string_opt : string -> nativeint option

Same as of_string , but return None instead of raising.

Since 4.05

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 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 .

val unsigned_compare : t -> t -> int

Same as Nativeint.compare , except that arguments are interpreted as unsigned native integers.

Since 4.08

val equal : t -> t -> bool

The equal function for native ints.

Since 4.03

val min : t -> t -> t

Return the smaller of the two arguments.

Since 4.13

val max : t -> t -> t

Return the greater of the two arguments.

Since 4.13

val popcount : t -> int

Population count, also known as Hamming weight. popcount n is the number of 1 bits in the binary representation of n . Negative n are represented in two's complement.

Since 5.5

val unsigned_bitsize : t -> int

unsigned_bitsize n is the minimal number of bits needed to represent n as an unsigned binary number. It is the smallest integer i between 0 and size inclusive such that 0 <= n < 2{^i} (unsigned).

Since 5.5

val signed_bitsize : t -> int

signed_bitsize n is the minimal number of bits needed to represent n as a signed, two's complement binary number. It is the smallest integer i between 1 and size inclusive such that -2{^i-1} <= n < 2{^i-1} (signed).

Since 5.5

val leading_zeros : t -> int

leading_zeros n is the number of leading (most significant) 0 bits in the binary representation of n . It is an integer between 0 and 64 inclusive. If n is negative, leading_zeros n = 0 since the most significant bit of n is 1. leading_zeros n = size if and only if n = zero . Note that leading_zeros n + unsigned_bitsize n = size .

Since 5.5

val leading_sign_bits : t -> int

leading_sign_bits n is the number of leading (most significant) sign bits in the binary representation of n , excluding the sign bit itself. It is an integer between 0 and 63 inclusive. For positive n , it is the number of leading zero bits minus one. For negative n , it is the number of leading one bits minus one. Note that leading_sign_bits n + signed_bitsize n = size .

Since 5.5

val trailing_zeros : t -> int

trailing_zeros n is the number of trailing (least significant) 0 bits in the binary representation of n . It is an integer between 0 and size inclusive. It is the largest integer i <= size such that 2{^i} divides n evenly. For example, trailing_zeros n = 0 if and only if n is odd, and trailing_zeros n = size if and only if n = zero .

Since 5.5

val seeded_hash : int -> t -> int

A seeded hash function for native ints, with the same output value as Hashtbl.seeded_hash . This function allows this module to be passed as argument to the functor Hashtbl.MakeSeeded .

Since 5.1

val hash : t -> int

An unseeded hash function for native ints, with the same output value as Hashtbl.hash . This function allows this module to be passed as argument to the functor Hashtbl.Make .

Since 5.1