Dispatching on a variant

[#ponce]

> Exactly, this is what I mentioned previously. Isn't it ugly compared to
> 
>   type Event = Mouse | Key | Move;
> 
>   void dispatchEvent(Event event) {
>     match(event) {
>       Mouse m => m.squeek();
>       Key k => ...
>       ...
>     }
>   }
> 
> What's with all the language proposals here? Why hasn't anyone proposed 
> this before? This is in fact very helpful - that's why several modern 
> languages have adopted it.

Algebraic data types are indeed a neat feature.
But the languages which implemented this (ML, Haskell, scala...) seems only to be functionals one. 
I suppose it's because it replaces enums and unions for those. In procedural languages one can emulate this with 1 enum + 1 union.

I would prefer having some computed goto (through final switch).