Buchhaltung.Zipper

Documentation

data Zipper a

Nonemtpy zipper

Constructors

LZ

Fields

• past :: E.NonEmpty a
• future :: [a]

Instances

Functor Zipper

Methods

fmap :: (a -> b) -> Zipper a -> Zipper b

(<$) :: a -> Zipper b -> Zipper a

present :: Zipper a -> a

integrate' :: Zipper a -> E.NonEmpty a

Re-constitute a list from a zipper context.

integrate :: Zipper a -> [a]

differentiate :: E.NonEmpty a -> Zipper a

Turn a list into a context with the focus on the first element.

back :: Zipper a -> Zipper a

Move the focus to the previous element. Do nothing if the focus | is already on the first element.

fwd :: Zipper a -> Zipper a

Move the focus to the next element. Do nothing if the focus is | already on the last element.

modifyPresent :: (a -> a) -> Zipper a -> Zipper a

Apply the given function to the currently focused element to | produce a new currently focused element.

modifyBack :: ([a] -> [a]) -> Zipper a -> Zipper a

Apply the given function to all elements preceding the focus.

modifyFwd :: ([a] -> [a]) -> Zipper a -> Zipper a

Apply the given function to all elements after the focus.

delete :: Zipper a -> Zipper a

Delete the currently focused element. If there are no future elements move the focus to the next last element.

insback :: a -> Zipper a -> Zipper a

Insert a new element just before the current focus, then move the | focus to the newly inserted element.

insfwd :: a -> Zipper a -> Zipper a

Insert a new element just after the current focus, then move the | focus to the newly inserted element.