module Stack:sig
..end
This module implements stacks (LIFOs), with in-place modification.
type 'a
t
'a
.exception Empty
val create : unit -> 'a t
val push : 'a -> 'a t -> unit
push x s
adds the element x
at the top of stack s
.val pop : 'a t -> 'a
pop s
removes and returns the topmost element in stack s
,
or raises Empty
if the stack is empty.val top : 'a t -> 'a
top s
returns the topmost element in stack s
,
or raises Empty
if the stack is empty.val clear : 'a t -> unit
val copy : 'a t -> 'a t
val is_empty : 'a t -> bool
true
if the given stack is empty, false
otherwise.val length : 'a t -> int
val 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.val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
fold f accu s
is (f (... (f (f accu x1) x2) ...) xn)
where x1
is the top of the stack, x2
the second element,
and xn
the bottom element. The stack is unchanged.