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105 lines
3.8 KiB
OCaml
105 lines
3.8 KiB
OCaml
(*
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Copyright (c) 2013, 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 Generators}
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Values of type ['a Gen.t] represent a possibly infinite sequence of values
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of type 'a. One can only iterate once on the sequence, as it is consumed
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by iteration/deconstruction/access. [None] is returned when the generator
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is exhausted. Most functions consume elements.
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The submodule {!Restart} provides utilities to work with
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{b restartable generators}, that is, functions [unit -> 'a Gen.t] that
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allow to build as many generators from the same source as needed.
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*)
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(** {2 Global type declarations} *)
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type 'a t = unit -> 'a option
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(** A generator may be called several times, yielding the next value
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each time. It returns [None] when no elements remain *)
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type 'a gen = 'a t
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(** {b NOTE}: version informations ("@since" annotations) in CCGen_intf
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will not be reliable, for they will represent versions of Gen
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rather than containers. *)
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module type S = Gen_intf.S
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(** {2 Transient generators} *)
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val get : 'a t -> 'a option
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(** Get the next value *)
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val next : 'a t -> 'a option
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(** Synonym for {!get} *)
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val get_exn : 'a t -> 'a
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(** Get the next value, or fails
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@raise Invalid_argument if no element remains *)
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val junk : 'a t -> unit
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(** Drop the next value, discarding it. *)
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val repeatedly : (unit -> 'a) -> 'a t
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(** Call the same function an infinite number of times (useful for instance
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if the function is a random generator). *)
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include S with type 'a t := 'a gen
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(** Operations on {b transient} generators *)
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(** {2 Restartable generators} *)
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module Restart : sig
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type 'a t = unit -> 'a gen
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type 'a restartable = 'a t
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include S with type 'a t := 'a restartable
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val cycle : 'a t -> 'a t
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(** Cycle through the enum, endlessly. The enum must not be empty. *)
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val lift : ('a gen -> 'b) -> 'a t -> 'b
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val lift2 : ('a gen -> 'b gen -> 'c) -> 'a t -> 'b t -> 'c
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end
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(** {2 Utils} *)
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val persistent : 'a t -> 'a Restart.t
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(** Store content of the transient generator in memory, to be able to iterate
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on it several times later. If possible, consider using combinators
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from {!Restart} directly instead. *)
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val persistent_lazy : 'a t -> 'a Restart.t
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(** Same as {!persistent}, but consumes the generator on demand (by chunks).
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This allows to make a restartable generator out of an ephemeral one,
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without paying a big cost upfront (nor even consuming it fully).
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@since 0.6.1 *)
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val start : 'a Restart.t -> 'a t
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(** Create a new transient generator.
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[start gen] is the same as [gen ()] but is included for readability. *)
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