Module CCZipper

module CCZipper: sig .. end

List Zipper


Since 1.0

type 'a t = 'a list * 'a list 
The pair l, r represents the list List.rev_append l r, but with the focus on r.
val empty : 'a t
Empty zipper
val is_empty : 'a t -> bool
Empty zipper? Returns true iff the two lists are empty.
val to_list : 'a t -> 'a list
Convert the zipper back to a list. to_list (l,r) is List.rev_append l r
val to_rev_list : 'a t -> 'a list
Convert the zipper back to a reversed list. In other words, to_list (l,r) is List.rev_append r l
val make : 'a list -> 'a t
Create a zipper pointing at the first element of the list
val left : 'a t -> 'a t
Go to the left, or do nothing if the zipper is already at leftmost pos
val left_exn : 'a t -> 'a t
Go to the left, or
Raises Invalid_argument if the zipper is already at leftmost pos
val right : 'a t -> 'a t
Go to the right, or do nothing if the zipper is already at rightmost pos
val right_exn : 'a t -> 'a t
Go to the right, or
Raises Invalid_argument if the zipper is already at rightmost pos
val modify : ('a option -> 'a option) -> 'a t -> 'a t
Modify the current element, if any, by returning a new element, or returning None if the element is to be deleted
val insert : 'a -> 'a t -> 'a t
Insert an element at the current position. If an element was focused, insert x l adds x just before it, and focuses on x
val remove : 'a t -> 'a t
remove l removes the current element, if any.
val is_focused : 'a t -> bool
Is the zipper focused on some element? That is, will CCZipper.focused return a Some v?
val focused : 'a t -> 'a option
Returns the focused element, if any. focused zip = Some _ iff empty zip = false
val focused_exn : 'a t -> 'a
Returns the focused element, or
Raises Not_found if the zipper is at an end
val drop_before : 'a t -> 'a t
Drop every element on the "left" (calling CCZipper.left then will do nothing).
val drop_after : 'a t -> 'a t
Drop every element on the "right" (calling CCZipper.right then will do nothing), keeping the focused element, if any.
val drop_after_and_focused : 'a t -> 'a t
Drop every element on the "right" (calling CCZipper.right then will do nothing), including the focused element if it is present.