89 lines
3.2 KiB
OCaml
89 lines
3.2 KiB
OCaml
(**************************************************************************)
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(* *)
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(* OCaml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* en Automatique. *)
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(* *)
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(* All rights reserved. This file is distributed under the terms of *)
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(* the GNU Lesser General Public License version 2.1, with the *)
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(* special exception on linking described in the file LICENSE. *)
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(* *)
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(**************************************************************************)
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(** Last-in first-out stacks.
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This module implements stacks (LIFOs), with in-place modification.
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*)
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type !'a t
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(** The type of stacks containing elements of type ['a]. *)
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exception Empty
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(** Raised when {!Stack.pop} or {!Stack.top} is applied to an empty stack. *)
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val create : unit -> 'a t
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(** Return a new stack, initially empty. *)
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val push : 'a -> 'a t -> unit
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(** [push x s] adds the element [x] at the top of stack [s]. *)
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val pop : 'a t -> 'a
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(** [pop s] removes and returns the topmost element in stack [s],
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or raises {!Empty} if the stack is empty. *)
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val pop_opt : 'a t -> 'a option
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(** [pop_opt s] removes and returns the topmost element in stack [s],
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or returns [None] if the stack is empty.
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@since 4.08 *)
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val top : 'a t -> 'a
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(** [top s] returns the topmost element in stack [s],
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or raises {!Empty} if the stack is empty. *)
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val top_opt : 'a t -> 'a option
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(** [top_opt s] returns the topmost element in stack [s],
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or [None] if the stack is empty.
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@since 4.08 *)
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val clear : 'a t -> unit
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(** Discard all elements from a stack. *)
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val copy : 'a t -> 'a t
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(** Return a copy of the given stack. *)
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val is_empty : 'a t -> bool
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(** Return [true] if the given stack is empty, [false] otherwise. *)
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val length : 'a t -> int
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(** Return the number of elements in a stack. Time complexity O(1) *)
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val iter : ('a -> unit) -> 'a t -> unit
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(** [iter f s] applies [f] in turn to all elements of [s],
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from the element at the top of the stack to the element at the
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bottom of the stack. The stack itself is unchanged. *)
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val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
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(** [fold f accu s] is [(f (... (f (f accu x1) x2) ...) xn)]
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where [x1] is the top of the stack, [x2] the second element,
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and [xn] the bottom element. The stack is unchanged.
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@since 4.03 *)
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(** {1 Iterators} *)
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val to_seq : 'a t -> 'a Seq.t
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(** Iterate on the stack, top to bottom.
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It is safe to modify the stack during iteration.
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@since 4.07 *)
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val add_seq : 'a t -> 'a Seq.t -> unit
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(** Add the elements from the iterator on the top of the stack.
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@since 4.07 *)
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val of_seq : 'a Seq.t -> 'a t
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(** Create a stack from the iterator
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@since 4.07 *)
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