A list that gives each element a locally unique Key for later modification or removal.

Convert a list using fromList or build one from scratch with empty and push.

An item identifier. Use with update and remove.

A list with no items.

Attach a new item to the beginning of the list.

Attach a new item to the end of the list.

Convert a List to a KeyedList, preserving the order of the items.

Update the value of a list for a specific Key with a given function.

Remove an item from a list by Key. If the Key is not found, no changes are made.

Convert to a regular List. Useful if you need to convert to JSON.

Create a List out of items and their Keys. This is particularly useful in the view of a Model that contains a KeyedList.

type alias Model =
    { submodels : KeyedList SubModel
      ...
    }


view : Model -> Html Msg
view model =
    keyedMap viewKeyedSubmodel model.submodels
        |> div []


viewKeyedSubmodel : Key -> SubModel -> Html Msg
viewKeyedSubmodel key submodel =
    div [ onClick <| Click key ] [ SubModel.view submodel ]

Check if a list is currently empty

Get the current length of a list

Keep only elements that satisfy the predicate, preserving Keys.

Apply a function to every item in a list, preserving Keys.