Previous  Up  Next

Module Stack

module Stack: sig .. end
Last-in first-out 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 Stack.pop or Stack.top is applied to an empty stack.
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 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
Discard all elements from a stack.
val copy : 'a t -> 'a t
Return a copy of the given 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.