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137 lines
4.5 KiB
OCaml
137 lines
4.5 KiB
OCaml
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(*
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copyright (c) 2013-2014, simon cruanes
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all rights reserved.
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redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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redistributions of source code must retain the above copyright notice, this
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list of conditions and the following disclaimer. redistributions in binary
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form must reproduce the above copyright notice, this list of conditions and the
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following disclaimer in the documentation and/or other materials provided with
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the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*)
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(** {1 Random Generators} *)
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type state = Random.State.t
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type 'a t = state -> 'a
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(** Random generator for values of type ['a] *)
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type 'a random_gen = 'a t
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val return : 'a -> 'a t
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(** [return x] is the generator that always returns [x].
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Example: [let random_int = return 4 (* fair dice roll *)] *)
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val flat_map : ('a -> 'b t) -> 'a t -> 'b t
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val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
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val map : ('a -> 'b) -> 'a t -> 'b t
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val (>|=) : 'a t -> ('a -> 'b) -> 'b t
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val delay : (unit -> 'a t) -> 'a t
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(** Delay evaluation. Useful for side-effectful generators that
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need some code to run for every call.
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Example:
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{[
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let gensym = let r = ref 0 in fun () -> incr r; !r ;;
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delay (fun () ->
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let name = gensym() in
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small_int >>= fun i -> return (name,i)
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)
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]}
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@since NEXT_RELEASE
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*)
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val choose : 'a t list -> 'a option t
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(** Choose a generator within the list. *)
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val choose_exn : 'a t list -> 'a t
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(** Same as {!choose} but without option.
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@raise Invalid_argument if the list is empty *)
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val choose_array : 'a t array -> 'a option t
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val choose_return : 'a list -> 'a t
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(** Choose among the list
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@raise Invalid_argument if the list is empty *)
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val replicate : int -> 'a t -> 'a list t
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(** [replace n g] makes a list of [n] elements which are all generated
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randomly using [g] *)
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val list_seq : 'a t list -> 'a list t
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(** Build random lists from lists of random generators
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@since NEXT_RELEASE *)
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val small_int : int t
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val int : int -> int t
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val int_range : int -> int -> int t
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(** Inclusive range *)
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val split : int -> (int * int) option t
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(** Split a positive value [n] into [n1,n2] where [n = n1 + n2].
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@return [None] if the value is too small *)
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val split_list : int -> len:int -> int list option t
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(** Split a value [n] into a list of values whose sum is [n]
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and whose length is [length].
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@return [None] if the value is too small *)
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val retry : ?max:int -> 'a option t -> 'a option t
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(** [retry g] calls [g] until it returns some value, or until the maximum
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number of retries was reached. If [g] fails,
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then it counts for one iteration, and the generator retries.
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@param max: maximum number of retries. Default [10] *)
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val try_successively : 'a option t list -> 'a option t
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(** [try_successively l] tries each generator of [l], one after the other.
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If some generator succeeds its result is returned, else the
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next generator is tried *)
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val (<?>) : 'a option t -> 'a option t -> 'a option t
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(** [a <?> b] is a choice operator. It first tries [a], and returns its
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result if successful. If [a] fails, then [b] is returned. *)
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val fix :
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?sub1:('a t -> 'a t) list ->
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?sub2:('a t -> 'a t -> 'a t) list ->
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?subn:(int t * ('a list t -> 'a t)) list ->
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base:'a t -> int t -> 'a t
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(** Recursion combinators, for building recursive values.
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The integer generator is used to provide fuel. The [sub_] generators
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should use their arguments only once!
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@param sub1 cases that recurse on one value
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@param sub2 cases that use the recursive gen twice
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@param subn cases that use a list of recursive cases *)
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(** {6 Applicative} *)
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val pure : 'a -> 'a t
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val (<*>) : ('a -> 'b) t -> 'a t -> 'b t
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(** {6 Run a generator} *)
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val run : ?st:state -> 'a t -> 'a
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(** Using a random state (possibly the one in argument) run a generator *)
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