26 lines
961 B
OCaml
26 lines
961 B
OCaml
(* Stacks *)
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(* This modl implements stacks (LIFOs), with in-place modification. *)
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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 [pop] is applied to an empty stack. *)
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val new: 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 clear : 'a t -> unit
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(* Discard all elements from a stack. *)
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val length: 'a t -> int
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(* Return the number of elements in a stack. *)
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val iter: ('a -> 'b) -> 'a t -> unit
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(* [iter f s] applies [f] in turn to all elements of [s], from the
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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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