Stdlib.Nativeint
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 232 or 264 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
Integer division. This division rounds the real quotient of its arguments towards zero, as specified for Stdlib.(/)
.
Same as div
, except that arguments and result are interpreted as unsigned native integers.
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
.
Same as rem
, except that arguments and result are interpreted as unsigned native integers.
abs x
is the absolute value of x
. On min_int
this is min_int
itself and thus remains negative.
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.
The greatest representable native integer, either 231 - 1 on a 32-bit platform, or 263 - 1 on a 64-bit platform.
The smallest representable native integer, either -231 on a 32-bit platform, or -263 on a 64-bit platform.
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.
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
.
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
.
Convert the given integer (type int
) to a native integer (type nativeint
).
Convert the given native integer (type nativeint
) to an integer (type int
). The high-order bit is lost during the conversion.
Same as to_int
, but interprets the argument as an unsigned integer. Returns None
if the unsigned value of the argument cannot fit into an int
.
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.
Convert the given native integer to a 32-bit integer (type int32
). On 64-bit platforms, the 64-bit native integer is taken modulo 232, i.e. the top 32 bits are lost. On 32-bit platforms, the conversion is exact.
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
.
Same as of_string
, but return None
instead of raising.
The comparison function for native integers, with the same specification as Stdlib.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
.
Same as compare
, except that arguments are interpreted as unsigned native integers.