Data.SelectionFoldableWithData

data SelectionFoldableWithData f d a

A Foldable where at most one item is selected, and the selected item has some extra data associated with it. The selected item is guaranteed to be in the Foldable structure. However, no guarantees are made regarding uniqueness of the items (see the README for more info).

The data constructor is kept private in order to maintain the desired invariants.

• f is the type of the Foldable that will contain the items.
• d is the type of the data associated with the optionally selected item.
• a is the type of the items.

Instances

• (Eq (f a), Eq d, Eq a) => Eq (SelectionFoldableWithData f d a)
• (Show (f a), Show d, Show a) => Show (SelectionFoldableWithData f d a)
• (Functor f) => Functor (SelectionFoldableWithData f d)
• (Foldable f) => Foldable (SelectionFoldableWithData f d)
• (FoldableWithIndex i f) => FoldableWithIndex i (SelectionFoldableWithData f d)
• (Functor f, Compactable f) => Compactable (SelectionFoldableWithData f d)
• (Filterable f) => Filterable (SelectionFoldableWithData f d)

type IsSelected = Boolean

A type alias used for better clarity in type signatures.

fromFoldable :: forall a d f. Foldable f => f a -> SelectionFoldableWithData f d a

Constructs a SelectionFoldableWithData from a Foldable structure of items.

toFoldable :: forall a d f. Foldable f => SelectionFoldableWithData f d a -> f a

Extracts the Foldable structure of items from a SelectionFoldableWithData.

select :: forall a d f. Foldable f => Eq a => d -> a -> SelectionFoldableWithData f d a -> SelectionFoldableWithData f d a

Selects the first element a such that a == x. If such an element is found, it is selected and the provided d is used as the associated data. If not, nothing happens.

selectWith :: forall a d f. Foldable f => (a -> Maybe d) -> SelectionFoldableWithData f d a -> SelectionFoldableWithData f d a

Selects the first element a such that p a == true. If such an element is found, it is selected and the provided function f is used to calculate the d to be used as the associated data. If not, nothing happens.

selectIndex :: forall a d f i. FoldableWithIndex i f => Eq i => (a -> d) -> i -> SelectionFoldableWithData f d a -> SelectionFoldableWithData f d a

Selects the element at index i' such that i' == i. If such an element is found, it is selected and the provided function p is used to calculate the d to be used as the associated data. If not, nothing happens.

selectWithIndex :: forall a d f i. FoldableWithIndex i f => (i -> a -> Maybe d) -> SelectionFoldableWithData f d a -> SelectionFoldableWithData f d a

Selects the first element a such that p i a == Just d where i is the index of a. If such an element is found, it is selected and the provided d is used as the associated data. If not, nothing happens.

deselect :: forall a d f. SelectionFoldableWithData f d a -> SelectionFoldableWithData f d a

Clears the selection and its associated data.

selected :: forall a d f. SelectionFoldableWithData f d a -> Maybe (Tuple d a)

Returns the selected item and its associated data as a Tuple (if they exist).

selected_ :: forall a d f. SelectionFoldableWithData f d a -> Maybe a

Returns the selected item (if it exists).

mapSelected :: forall b e a d f. Foldable f => Functor f => Eq a => { rest :: a -> b, sel :: Tuple d a -> Tuple e b } -> SelectionFoldableWithData f d a -> SelectionFoldableWithData f e b

If there exist multiple elements a such that p a == true, the function will be invoked with true as the first argument. No guarantee of uniqueness is made; that is left up to the user.

foldrSelected :: forall b a d f. Foldable f => Eq a => { rest :: a -> b -> b, sel :: Tuple d a -> b -> b } -> b -> SelectionFoldableWithData f d a -> b

Performs a foldr, using the provided functions to transform the items and the data. The sel function is used for all items a that are equal to the selected item, and the rest function is used for the other items.

foldrWithIndexSelected :: forall b a d f i. FoldableWithIndex i f => Eq a => { rest :: i -> a -> b -> b, sel :: i -> Tuple d a -> b -> b } -> b -> SelectionFoldableWithData f d a -> b

Performs a foldrWithIndex, using the provided functions to transform the items and the data. The sel function is used for all items a that are equal to the selected item, and the rest function is used for the other items.

foldlSelected :: forall b a d f. Foldable f => Eq a => { rest :: b -> a -> b, sel :: b -> Tuple d a -> b } -> b -> SelectionFoldableWithData f d a -> b

Performs a foldl, using the provided functions to transform the items and the data. The sel function is used for all items a that are equal to the selected item, and the rest function is used for the other items.

foldlWithIndexSelected :: forall b a d f i. FoldableWithIndex i f => Eq a => { rest :: i -> b -> a -> b, sel :: i -> b -> Tuple d a -> b } -> b -> SelectionFoldableWithData f d a -> b

Performs a foldlWithIndex, using the provided functions to transform the items and the data. The sel function is used for all items a that are equal to the selected item, and the rest function is used for the other items.