From: Harry Ohlsen <harryo@...>
Date: 2001-12-12T08:03:47+09:00
Subject: [ruby-talk:28287] Re: The benefits of dynamic typing?

In article
<Pine.GSO.4.21.0112111556050.2917-100000@godzilla.ce.chalmers.se>, "Robert
Feldt" <feldt@ce.chalmers.se> wrote:


> Something like
> 
> class T
>   type_hint Integer, :m, Integer, Integer
>  def m(a,b)
>     a+b
>   end
> end

I assume what this means is that the method is intended to return
Integer, and the arguments are both intended to be Integer, hence the VM
is being asked to do appropriate conversions, if possible, if the actual
arguments passed (or the return value) don't match?

Ie, if I wanted T#fred to return String and take two arguments of types
Fixnum and Float, I'd do something like ...

 class T
     type_hint String, :fred, Fixnum, Float
    def fred(a,b)
         a+b
     end
 end


I think that's very nice.  In particular, it would make writing classes
for mathematical types nice and clean.  At the moment, one needs to write
a lot of short pieces of code to do coercions, just in case you want to
mix your own types with already-existing ones.