NAME¶
Random - Pseudo-random number generators (PRNG).
Module¶
Module Random
Documentation¶
Module
Random
:
sig end
Pseudo-random number generators (PRNG).
=== Basic functions ===
val init :
int -> unit
Initialize the generator, using the argument as a seed. The same seed will
always yield the same sequence of numbers.
val full_init :
int array -> unit
Same as
Random.init but takes more data as seed.
val 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).
val bits :
unit -> int
Return 30 random bits in a nonnegative integer.
Before3.12.0 used a different algorithm (affects all the following
functions)
val int :
int -> int
Random.int bound returns a random integer between 0 (inclusive) and
bound (exclusive).
bound must be greater than 0 and less than
2^{30.
val int32 :
Int32.t -> Int32.t
Random.int32 bound returns a random integer between 0 (inclusive) and
bound (exclusive).
bound must be greater than 0.
val nativeint :
Nativeint.t -> Nativeint.t
Random.nativeint bound returns a random integer between 0 (inclusive) and
bound (exclusive).
bound must be greater than 0.
val int64 :
Int64.t -> Int64.t
Random.int64 bound returns a random integer between 0 (inclusive) and
bound (exclusive).
bound must be greater than 0.
val float :
float -> float
Random.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.
val bool :
unit -> bool
Random.bool () returns
true or
false with probability 0.5
each.
=== 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. ===
module State : sig end
val get_state :
unit -> State.t
Return the current state of the generator used by the basic functions.
val set_state :
State.t -> unit
Set the state of the generator used by the basic functions.
