Haskell pattern matching not allowed in Elm?

Question

Following this Elm tutorial and I assumed that the function

update : Msg -> Model -> Model

is defined in the tutorial as

update msg model = 
    case msg of
        Increment  -> model + 1
        Deccrement -> model - 1
        Reset      -> 0

I thought I would define it the same way but with syntax I prefer:

update Increment model = model + 1
update Decrement model = model - 1
update Reset model     = 0

But this doesn't compile, does Elm not support this syntax or did I make a mistake?

Answer 1

One of the goals of Elm is to use a consistent style; removing redundant syntax is a conclusion of this. For that reason, you will not find any where clause and function definitions with multiple variants are not permitted either.