package ocaml-base-compiler
Last-in first-out stacks.
This module implements stacks (LIFOs), with in-place modification.
val create : unit -> 'a t
Return a new stack, initially empty.
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 pop_opt : 'a t -> 'a option
pop_opt s
removes and returns the topmost element in stack s
, or returns None
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 top_opt : 'a t -> 'a option
top_opt s
returns the topmost element in stack s
, or None
if the stack is empty.
val clear : 'a t -> unit
Discard all elements from a stack.
val is_empty : 'a t -> bool
Return true
if the given stack is empty, false
otherwise.
val length : 'a t -> int
Return the number of elements in a stack. Time complexity O(1)
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.
Stacks and Sequences
Iterate on the stack, top to bottom. It is safe to modify the stack during iteration.