Module PS.CQueue

Priority queues on clauses

module C : module type of struct include C end with type t = C.t
module WeightFun : sig ... end
type t

A priority queue.

val add : t -> C.t -> unit

Add a clause to the Queue

val add_seq : t -> C.t Iter.t -> unit

Add clauses to the queue

val length : t -> int

Number of elements

val is_empty : t -> bool

check whether the queue is empty

val take_first : t -> C.t

Take first element of the queue, or raise Not_found

val name : t -> string

Name of the implementation/role of the queue

Available Queues
val make : ratio:int -> weight:(C.t -> int) -> string -> t

Bring your own implementation of queue.

  • parameter ratio

    pick-given ratio. One in ratio calls to take_first, the returned clause comes from a FIFO; the other times it comes from a priority queue that uses weight to sort clauses

  • parameter name

    the name of this clause queue

val bfs : unit -> t

FIFO

val almost_bfs : unit -> t

Half FIFO, half default

val explore : unit -> t

Use heuristics for selecting "small" clauses

val ground : unit -> t

Favor positive unit clauses and ground clauses

val goal_oriented : unit -> t

custom weight function that favors clauses that are "close" to initial conjectures. It is fair.

val default : unit -> t

Obtain the default queue

Select the queue corresponding to the given profile

IO
val to_string : t -> string