Module

Data.SelectionFoldableWithData

#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

#IsSelected 

type IsSelected = Boolean

A type alias used for better clarity in type signatures.

#fromFoldable 

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

Constructs a SelectionFoldableWithData from a Foldable structure of items.

#toFoldable 

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

Extracts the Foldable structure of items from a SelectionFoldableWithData.

#select 

select :: forall f d a. 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 

selectWith :: forall f d a. 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 

selectIndex :: forall i f d a. 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 

selectWithIndex :: forall i f d a. 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 

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

Clears the selection and its associated data.

#selected 

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

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

#selected_ 

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

Returns the selected item (if it exists).

#mapSelected 

mapSelected :: forall f d a e b. 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 

foldrSelected :: forall f d a b. 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 

foldrWithIndexSelected :: forall i f d a b. 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 

foldlSelected :: forall f d a b. 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 

foldlWithIndexSelected :: forall i f d a b. 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.

Modules