[Neko] Type Classes... (kind of)

[Nicolas Cannasse]

Stephane Le Dorze a écrit :
> I really like to stretch the capabilities of Haxe language...

This discussion would be more appropriate on haXe list, but I'll answer
here :)

> I think that a very interesting extension of the inferencer would be
> typedef Union so that we could use the duck typing this way:
> 
> class Peon {
>     public    function    new()    {
>     }
>     public function say ()    {
>     }
>     public function die ()    {
>     }
>     public    function sleep ()    {
>     }
> }
> 
> typedef SayDie = {    say : Void -> Void, die : Void -> Void    }
> typedef Sleep = {    sleep : Void -> Void    }
> 
> var l = new List<SayDie, Sleep>();
> l.add(peon);


You already have the following in haXe :

var s : SayDie = new Peon();

And :

var l = new List<Sleep>();
l.add(new Peon());

So there is already duck typing / type classes in haXe.

The only thing is that there is no syntax currently to composite two
typedefs together, but you can extend one with more definitions :

typedef SleepSayDie = {> SayDie, sleep : Void -> Void }

Nicolas