Re: [Chicken-hackers] deprecation of always?, never?, none?

[Felix]

From: Thomas Chust <address@hidden>
Subject: Re: [Chicken-hackers] deprecation of always?, never?, none?
Date: Mon, 22 Aug 2011 16:43:58 +0200

> Felix wrote:
>> [...]
>> "none?" is sort of weird, since there is no "none" type - every object
>> is of some type.
>> [...]
> 
> Hello,
> 
> that doesn't make none less of a type and it also doesn't make it less
> useful — for example, in the context of type checking, you may want to
> represent the fact that a function can never exit through its return
> continuation by assigning the none return type to it.

That's a matter of control flow, not of type. Bottom is not a value,
it is undefinedness, in every sense.


cheers,
felix