package stdlib-random

  1. Overview
  2. Docs
Versioned Random module from the OCaml standard library

Install

Dune Dependency

Authors

Maintainers

Sources

1.2.0.tar.gz
md5=d6e6e33381df77c088fc053512fc3c4c
sha512=74106d17d4866989895b913dc8b83c6fdce33e7969767c0fb2b250e0f62ea398e93d5188cd07aa4868bdcdcc9f99137b72ce594bf441f5268e3b78016694cac9

doc/stdlib-random.v4/Random4/index.html

Module Random4Source

Pseudo-random number generators (PRNG).

Basic functions

Sourceval init : int -> unit

Initialize the generator, using the argument as a seed. The same seed will always yield the same sequence of numbers.

Sourceval full_init : int array -> unit

Same as Random4.init but takes more data as seed.

Sourceval self_init : unit -> unit

Initialize the generator with a random seed chosen in a system-dependent way. If /dev/urandom is available on the host machine, it is used to provide a highly random initial seed. Otherwise, a less random seed is computed from system parameters (current time, process IDs).

Sourceval bits : unit -> int

Return 30 random bits in a nonnegative integer.

Sourceval int : int -> int

Random4.int bound returns a random integer between 0 (inclusive) and bound (exclusive). bound must be greater than 0 and less than 230.

Sourceval full_int : int -> int

Random4.full_int bound returns a random integer between 0 (inclusive) and bound (exclusive). bound may be any positive integer.

If bound is less than 231, then Random4.full_int bound yields identical output across systems with varying int sizes.

If bound is less than 230, then Random4.full_int bound is equal to Random4.int bound.

If bound is at least 230 (on 64-bit systems, or non-standard environments such as JavaScript), then Random4.full_int returns a value whereas Random4.int raises Stdlib.Invalid_argument.

  • since 4.13
Sourceval int_in_range : min:int -> max:int -> int

Random4.int_in_range ~min ~max returns a random integer between min (inclusive) and max (inclusive). Both min and max are allowed to be negative; min must be less than or equal to max.

If both bounds fit in 32-bit signed integers (that is, if -231 <= min and max < 231), then int_in_range yields identical output across systems with varying int sizes.

  • since 5.2
Sourceval int32 : Int32.t -> Int32.t

Random4.int32 bound returns a random integer between 0 (inclusive) and bound (exclusive). bound must be greater than 0.

Sourceval int32_in_range : min:int32 -> max:int32 -> int32

Random4.int32_in_range ~min ~max returns a random integer between min (inclusive) and max (inclusive). Both min and max are allowed to be negative; min must be less than or equal to max.

  • since 5.2
Sourceval nativeint : Nativeint.t -> Nativeint.t

Random4.nativeint bound returns a random integer between 0 (inclusive) and bound (exclusive). bound must be greater than 0.

Sourceval nativeint_in_range : min:nativeint -> max:nativeint -> nativeint

Random4.nativeint_in_range ~min ~max returns a random integer between min (inclusive) and max (inclusive). Both min and max are allowed to be negative; min must be less than or equal to max.

  • since 5.2
Sourceval int64 : Int64.t -> Int64.t

Random4.int64 bound returns a random integer between 0 (inclusive) and bound (exclusive). bound must be greater than 0.

Sourceval int64_in_range : min:int64 -> max:int64 -> int64

Random4.int64_in_range ~min ~max returns a random integer between min (inclusive) and max (inclusive). Both min and max are allowed to be negative; min must be less than or equal to max.

  • since 5.2
Sourceval float : float -> float

Random4.float bound returns a random floating-point number between 0 and bound (inclusive). If bound is negative, the result is negative or zero. If bound is 0, the result is 0.

Sourceval bool : unit -> bool

Random4.bool () returns true or false with probability 0.5 each.

Sourceval bits32 : unit -> Int32.t

Random4.bits32 () returns 32 random bits as an integer between Int32.min_int and Int32.max_int.

Sourceval bits64 : unit -> Int64.t

Random4.bits64 () returns 64 random bits as an integer between Int64.min_int and Int64.max_int.

  • since 4.14
Sourceval nativebits : unit -> Nativeint.t

Random4.nativebits () returns 32 or 64 random bits (depending on the bit width of the platform) as an integer between Nativeint.min_int and Nativeint.max_int.

  • since 4.14

Advanced functions

The functions from module State manipulate the current state of the random generator explicitly. This allows using one or several deterministic PRNGs, even in a multi-threaded program, without interference from other parts of the program.

Sourcemodule State : sig ... end
Sourceval get_state : unit -> State.t

Return the current state of the generator used by the basic functions.

Sourceval set_state : State.t -> unit

Set the state of the generator used by the basic functions.

OCaml

Innovation. Community. Security.