package batteries

  1. Overview
  2. Docs
package batteries
Legend:
Library
Module
Module type
Parameter
Class
Class type

First-in first-out queues.

This module implements queues (FIFOs), with in-place modification.

  • author Xavier Leroy (Base module)
  • author David Teller
type 'a t = 'a Queue.t

The type of queues containing elements of type 'a.

exception Empty

Raised when Queue.take or Queue.peek is applied to an empty queue.

val create : unit -> 'a t

Return a new queue, initially empty.

val add : 'a -> 'a t -> unit

add x q adds the element x at the end of the queue q.

val push : 'a -> 'a t -> unit

push is a synonym for add.

val take : 'a t -> 'a

take q removes and returns the first element in queue q, or raises Empty if the queue is empty.

val pop : 'a t -> 'a

pop is a synonym for take.

val peek : 'a t -> 'a

peek q returns the first element in queue q, without removing it from the queue, or raises Empty if the queue is empty.

val top : 'a t -> 'a

top is a synonym for peek.

val clear : 'a t -> unit

Discard all elements from a queue.

val copy : 'a t -> 'a t

Return a copy of the given queue.

val is_empty : 'a t -> bool

Return true if the given queue is empty, false otherwise.

val length : 'a t -> int

Return the number of elements in a queue.

val iter : ('a -> unit) -> 'a t -> unit

iter f q applies f in turn to all elements of q, from the least recently entered to the most recently entered. The queue itself is unchanged.

val map : ('a -> 'b) -> 'a t -> 'b t

map f q applies function f to each element of the queue and returns a new queue q' with the results returned by f. Order is preserved and q is not consumed. So that if take q returns x take q' will return f x.

  • since 2.3.0
val filter : ('a -> bool) -> 'a t -> 'a t

filter p q returns a new queue that contain the elements of q that satisfy the predicate p, in the same order.

  • since 2.4
val filter_map : ('a -> 'b option) -> 'a t -> 'b t

filter_map f q applies f to the elements a0,a1..an of q in order, and returns the queue of the elements bi such that f ai = Some bi, in the corresponding order.

  • since 2.4
val filter_inplace : ('a -> bool) -> 'a t -> unit

filter_inplace p q removes all the elements of the queue q that don't satisfy the predicate p. The order of the elements in the queue is preserved.

  • since 2.4
val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b

fold f accu q is equivalent to List.fold_left f accu l, where l is the list of q's elements. The queue remains unchanged.

val transfer : 'a t -> 'a t -> unit

transfer q1 q2 adds all of q1's elements at the end of the queue q2, then clears q1. It is equivalent to the sequence iter (fun x -> add x q2) q1; clear q1, but runs in constant time.

type 'a enumerable = 'a t
val enum : 'a t -> 'a BatEnum.t

enum q returns a destructive enumeration of the elements of queue q, from the least recently entered to the most recently entered. Reading the enumeration will progressively empty q.

val of_enum : 'a BatEnum.t -> 'a t

of_enum e returns a new queue containing all the elements of e. This is equivalent to calling push with the first element of the enumeration, then with the second, etc.

Boilerplate code
Printing
val print : ?first:string -> ?last:string -> ?sep:string -> ('a BatInnerIO.output -> 'b -> unit) -> 'a BatInnerIO.output -> 'b t -> unit
val compare : 'a BatOrd.comp -> 'a t BatOrd.comp
val equal : 'a BatOrd.eq -> 'a t BatOrd.eq
module Exceptionless : sig ... end