Possibly

In short:

Never marks states as impossible

top : Empty Never (StackFilled element) -> element

Possibly marks states as possible
```
empty : Empty Possibly filling_
```

→ you can carry over non-emptiness-information

import Fillable exposing (Empty(..), toFillingOrIfEmpty)


type FocusHole possiblyOrNever item
    = Item item
    | Hole possiblyOrNever


toFocus :
    Empty possiblyOrNever value
    -> FocusHole possiblyOrNever value
toFocus =
    \fillable ->
        case fillable of
            Empty possiblyOrNever ->
                Hole possiblyOrNever


            Filled value ->
                value |> Item

toFocus =
    \fillable ->
        fillable
            |> Fillable.map Item
            |> toFillingOrIfEmpty Hole

type Possibly

= Possible

Marks a state as possible to occur.

in results

fromMaybe : Maybe value -> Empty Possibly value


fromList : List element -> Empty Possibly (StackFilled element)

in type declarations

type alias Model =
    WithoutConstructorFunction
        { selected : Empty Possibly Choice
        , planets : Empty Possibly (StackFilled Planet)
        , searchKeyWords : Empty Never (StackFilled String)
        }


type alias WithoutConstructorFunction record =
    record

where WithoutConstructorFunction stops the compiler from creating a positional constructor function for Model.

Read more about the general idea in the module documentation. or readme.

If you still have questions, check out the readme.

Modules

Possibly

lue-bird/elm-allowable-state/1.0.2

Possibly

in results

in type declarations

Modules