module CCRandom: sig .. end
Random Generators
type Random.State.t
type 'a t = state -> 'a
Random generator for values of type 'a
type 'a random_gen = 'a t
val return : 'a -> 'a t
return x is the generator that always returns x.
Example: let random_int = return 4
val flat_map : ('a -> 'b t) -> 'a t -> 'b t
val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
val map : ('a -> 'b) -> 'a t -> 'b t
val (>|=) : 'a t -> ('a -> 'b) -> 'b t
val delay : (unit -> 'a t) -> 'a t
Delay evaluation. Useful for side-effectful generators that
need some code to run for every call.
Example:
let gensym = let r = ref 0 in fun () -> incr r; !r ;;
delay (fun () ->
let name = gensym() in
small_int >>= fun i -> return (name,i)
)
Since 0.4
val choose : 'a t list -> 'a option t
Choose a generator within the list.
val choose_exn : 'a t list -> 'a t
Same as
CCRandom.choose but without option.
Raises Invalid_argument if the list is empty
val choose_array : 'a t array -> 'a option t
val choose_return : 'a list -> 'a t
Choose among the list
Raises Invalid_argument if the list is empty
val replicate : int -> 'a t -> 'a list t
replicate n g makes a list of n elements which are all generated
randomly using g
val sample_without_replacement : ?compare:('a -> 'a -> int) -> int -> 'a t -> 'a list t
sample_without_replacement n g makes a list of n elements which are all
generated randomly using g with the added constraint that none of the generated
random values are equal
Since 0.15
Raises Invalid_argument if n <= 0
val list_seq : 'a t list -> 'a list t
Build random lists from lists of random generators
Since 0.4
exception Pick_from_empty
Since 0.16
val pick_list : 'a list -> 'a t
Pick an element at random from the list
Since 0.16
Raises Pick_from_empty if the list is empty
val pick_array : 'a array -> 'a t
Pick an element at random from the array
Since 0.16
Raises Pick_from_empty if the array is empty
val small_int : int t
val int : int -> int t
val int_range : int -> int -> int t
Inclusive range
val small_float : float t
A reasonably small float.
Since 0.6.1
val float : float -> float t
Random float within the given range
Since 0.6.1
val float_range : float -> float -> float t
Inclusive range. float_range a b assumes a < b.
Since 0.6.1
val split : int -> (int * int) option t
Split a positive value n into n1,n2 where n = n1 + n2.
Returns None if the value is too small
val split_list : int -> len:int -> int list option t
Split a value n into a list of values whose sum is n
and whose length is length. The list is never empty and does not
contain 0.
Raises Invalid_argument if len <= 1
Returns None if the value is too small
val retry : ?max:int -> 'a option t -> 'a option t
retry g calls g until it returns some value, or until the maximum
number of retries was reached. If g fails,
then it counts for one iteration, and the generator retries.
val try_successively : 'a option t list -> 'a option t
try_successively l tries each generator of l, one after the other.
If some generator succeeds its result is returned, else the
next generator is tried
val (<?>) : 'a option t -> 'a option t -> 'a option t
a <?> b is a choice operator. It first tries a, and returns its
result if successful. If a fails, then b is returned.
val fix : ?sub1:('a t -> 'a t) list ->
?sub2:('a t -> 'a t -> 'a t) list ->
?subn:(int t * ('a list t -> 'a t)) list ->
base:'a t -> int t -> 'a t
Recursion combinators, for building recursive values.
The integer generator is used to provide fuel. The sub_ generators
should use their arguments only once!
sub1 : cases that recurse on one value
sub2 : cases that use the recursive gen twice
subn : cases that use a list of recursive cases
Applicative
val pure : 'a -> 'a t
val (<*>) : ('a -> 'b) t -> 'a t -> 'b t
Run a generator
val run : ?st:state -> 'a t -> 'a
Using a random state (possibly the one in argument) run a generator