stack: stacks

This module implements stacks (LIFOs), with in-place modification.
type 'a t
The type of stacks containing elements of type 'a.
exception Empty
Raised when pop is applied to an empty stack.
value new: unit -> 'a t
Return a new stack, initially empty.
value push: 'a -> 'a t -> unit
push x s adds the element x at the top of stack s.
value pop: 'a t -> 'a
pop s removes and returns the topmost element in stack s, or raises Empty if the stack is empty.
value clear : 'a t -> unit
Discard all elements from a stack.
value length: 'a t -> int
Return the number of elements in a stack.
value iter: ('a -> unit) -> 'a t -> unit
iter 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.