For my computer languages class I decided to evaluate Elm. Having not spend as much time on functional languages as I would have liked I figured this would be a good oportunity to expand my functional programming brain. These simple examples are the result of doing the exercises found in the Elm Documentation.
Forms
This first example is a basic form with validation. I augmented the form tutorial from the Elm Docs. My source can be found here.
The exercises in the tutorial were to augment the form in the following ways:
- Check that the password is longer than 8 characters.
- Make sure the password contains upper case, lower case, and numeric characters.
- Add an additional field for age and check that it is a number.
- Add a "Submit" button. Only show errors after it has been pressed.
Random Dice
The random tutorial can be found here.
I augmented the example provided in the following ways:
- show image for dice
- take input from user and validate
- allow arbitrary number of dice each with it's own random number
Again the source is found on GitHub here.
The main trick here is to augment the model to contain a list of dice and then update it with a generator that generates a new list of dice based on the numDice in the model.
type alias Model =
{ dice : (List Int)
, numDice : Int
}
...
update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
case msg of
Roll ->
(model, Random.generate NewDice (dieGenerator model.numDice))
NewDice dice ->
({ model | numDice = dice }, Cmd.none)