ocaml/stdlib/queue.mli

42 lines
1.8 KiB
OCaml

(***********************************************************************)
(* *)
(* Caml Special Light *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1995 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Module [Queues]: queues *)
(* This module implements queues (FIFOs), with in-place modification. *)
type 'a t
(* The type of queues containing elements of type ['a]. *)
exception Empty
(* Raised when [take] is applied to an empty queue. *)
val new: 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 take: 'a t -> 'a
(* [take q] removes and returns the first element in queue [q],
or raises [Empty] if the queue is empty. *)
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 clear : 'a t -> unit
(* Discard all elements from a queue. *)
val length: 'a t -> int
(* Return the number of elements in a queue. *)
val iter: ('a -> 'b) -> 'a t -> unit
(* [Queue.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. *)