Documentation

The implementation of the pointed list structure which tracks the current position in the list structure.

Lens compatible with Control.Lens.

Create a PointedList with a single element.

Possibly create a Just PointedList if the provided list has at least one element; otherwise, return Nothing.

The provided list's head will be the focus of the list, and the rest of list will follow on the right side.

Possibly create a Just PointedList if the provided list has at least one element; otherwise, return Nothing.

The provided list's last element will be the focus of the list, following the rest of the list in order, to the left.

Replace the focus of the list, retaining the prefix and suffix.

An alias for insertRight.

Insert an element to the left of the focus, then move the focus to the new element.

Insert an element to the right of the focus, then move the focus to the new element.

Delete all elements in the list except the focus.

The length of the list.

Create a PointedList of variations of the provided PointedList, in which each element is focused, with the provided PointedList as the focus of the sets.

Map over the PointedLists created via positions, such that f is called with each element of the list focused in the provided PointedList. An example makes this easier to understand:

contextMap atStart (fromJust $ fromList [1..5])

Create a PointedList a of (a, Bool), in which the boolean values specify whether the current element has the focus. That is, all of the booleans will be False, except the focused element.

Move the focus to the specified element, if it is present.

Patch with much faster algorithm provided by Runar Bjarnason for version 0.3.2. Improved again by Runar Bjarnason for version 0.3.3 to support infinite lists on both sides of the focus.

The index of the focus, leftmost is 0.

Move the focus to the next element in the list. If the last element is currently focused, loop to the first element.

Move the focus to the previous element in the list. If the first element is currently focused, loop to the last element.

An alias of deleteRight.

Possibly delete the element at the focus, then move the element on the left to the focus. If no element is on the left, focus on the element to the right. If the deletion will cause the list to be empty, return Nothing.

Possibly delete the element at the focus, then move the element on the right to the focus. If no element is on the right, focus on the element to the left. If the deletion will cause the list to be empty, return Nothing.

Move