Helpers for 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.
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.(/).
x mod y
is the integer remainder.
If y <> zero
, the result of x mod y
satisfies the following properties:
zero <= x mod y < abs y
and
x = ((x / y) * y) + (x mod y)
.
If y = 0
, x mod y
raises Division_by_zero
.
x lsl 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.
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 >= bitsize
.
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 >= bitsize
.
module Infix : sig ... end
val to_int : t ‑> int
Convert the given native integer (type nativeint
) to an
integer (type int
). The high-order bit is lost
during the conversion.
val of_int : int ‑> t
Alias to Nativeint.of_int.
Convert the given integer (type int
) to a native integer (type nativeint
).
val of_float : float ‑> t
Alias to Nativeint.of_float. Convert the given floating-point number to a native integer, discarding the fractional part (truncate towards 0). The result of the conversion is undefined if, after truncation, the number is outside the range [CCNativeint.min_int, CCNativeint.max_int].
val of_string_exn : string ‑> t
Alias to Nativeint.of_string.
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*CCNativeint.max_int+1]
. If the input exceeds CCNativeint.max_int
it is converted to the signed integer
CCInt64.min_int + input - CCNativeint.max_int - 1
.
Raise Failure "Nativeint.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 nativeint
.
val of_string : string ‑> t option
Safe version of of_string_exn.
Like of_string_exn, but return None
instead of raising.