module Stack: sig end
This module implements stacks (LIFOs), with in-place modification.
type 'a t
'a.exception Empty
val create : unit -> 'a tval push : 'a -> 'a t -> unitpush x s adds the element x at the top of stack s.val pop : 'a t -> 'apop s removes and returns the topmost element in stack s,
or raises Empty if the stack is empty.val top : 'a t -> 'atop s returns the topmost element in stack s,
or raises Empty if the stack is empty.val clear : 'a t -> unitval copy : 'a t -> 'a tval is_empty : 'a t -> booltrue if the given stack is empty, false otherwise.val length : 'a t -> intval iter : ('a -> unit) -> 'a t -> unititer f s applies f in turn to all elements of s,
from the element at the top of the stack to the element at the
bottom of the stack. The stack itself is unchanged.