Logic.Judge.PointedList

Re-export PointedList with convenience functions.

Documentation

asList :: PointedList a -> [a]

Turn a PointedList into a non-pointed list, assuming no particular ordering.

toList :: Foldable t => forall a. t a -> [a]

List of elements of a structure, from left to right.

current :: PointedList a -> a

Get the current focus of a PointedList.

insertAll :: Traversable t => t a -> Maybe (PointedList a) -> Maybe (PointedList a)

Add a number of entries to a possibly empty PointedList.

focus :: PointedList a -> [PointedList a]

Create a list of variations of the provided PointedList, one for each element to take focus.

This function is a bit sloppy. It assumes no particular order. Note that using toList instead can cause longer (or shorter?) running times.

modify :: PointedList a -> (a -> Maybe a) -> Maybe (PointedList a)

Update the focused element of a PointedList using a function that returns Just the new value, or Nothing for deletion.

update :: PointedList a -> Maybe a -> Maybe (PointedList a)

Update the focused element of a PointedList with the value of the Just, or delete the element if that value is Nothing.