CCNativeint
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.
include module type of struct include Nativeint end
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.
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). The result of the conversion is undefined if, after truncation, the number is outside the range [Nativeint
.min_int, Nativeint
.max_int].
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.
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.
val hash : t -> int
hash x
computes the hash of x
. Like Stdlib
.abs (to_int x).
val sign : t -> int
sign x
return 0
if x = 0
, -1
if x < 0
and 1
if x > 0
. Same as compare x zero
.
pow base exponent
returns base
raised to the power of exponent
. pow x y = x^y
for positive integers x
and y
. Raises Invalid_argument
if x = y = 0
or y
< 0.
floor_div x n
is integer division rounding towards negative infinity. It satisfies x = m * floor_div x n + rem x n
.
type 'a printer = Format.formatter -> 'a -> unit
type 'a random_gen = Random.State.t -> 'a
range_by ~step i j
iterates on integers from i
to j
included, where the difference between successive elements is step
. Use a negative step
for a decreasing list.
range i j
iterates on integers from i
to j
included . It works both for decreasing and increasing ranges.
range' i j
is like range
but the second bound j
is excluded. For instance range' 0 5 = Iter.of_list [0;1;2;3;4]
.
val random : t -> t random_gen
val random_small : t random_gen
val random_range : t -> t -> t random_gen
val of_string : string -> t option
of_string s
is the safe version of of_string_exn
. Like of_string_exn
, but return None
instead of raising.
val of_string_exn : string -> t
of_string_exn s
converts the given string s
into a native integer. 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 to_string_binary : t -> string
to_string_binary x
returns the string representation of the integer x
, in binary.
module Infix : sig ... end
include module type of Infix
x / y
is the integer quotient of x
and y
. Integer division. Raise Division_by_zero
if the second argument y
is zero. This division rounds the real quotient of its arguments towards zero, as specified for Stdlib.(/)
.
x mod y
is the integer remainder of x / y
. 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
.