Base.Random
Pseudo-random number generation.
This is a wrapper of the standard library's Random
library, though it does not share state with that library.
Note that all of these "basic" functions mutate a global random state.
Initialize the generator, using the argument as a seed. The same seed will always yield the same sequence of numbers.
Same as Random.init
but takes more data as seed.
Initialize the generator with a more-or-less random seed chosen in a system-dependent way. By default, self_init
is disallowed in inline tests, as it's often used for no good reason and it just creates nondeterministic failures for everyone. Passing ~allow_in_tests:true
removes this restriction in case you legitimately want nondeterministic values, like in Filename.temp_dir
.
Random.int bound
returns a random integer between 0 (inclusive) and bound
(exclusive). bound
must be greater than 0.
Random.int32 bound
returns a random integer between 0 (inclusive) and bound
(exclusive). bound
must be greater than 0.
Random.nativeint bound
returns a random integer between 0 (inclusive) and bound
(exclusive). bound
must be greater than 0.
Random.int64 bound
returns a random integer between 0 (inclusive) and bound
(exclusive). bound
must be greater than 0.
Random.float bound
returns a random floating-point number between 0 (inclusive) and bound
(exclusive). If bound
is negative, the result is negative or zero. If bound
is 0, the result is 0.
Produces a random value between the given inclusive bounds. Raises if bounds are given in decreasing order.
Produces a value between the given bounds (inclusive and exclusive, respectively). Raises if bounds are given in decreasing order.
Return a uniformly-chosen char
.
Return a uniformly-chosen char
in the ASCII range.
module State : sig ... end
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.
val set_state : State.t -> unit
Sets the state of the generator used by the basic functions.