Latest const expansion

[Bruno Medeiros]

Bill Baxter wrote:
> Regan Heath wrote:
>> const(T)  indicates both head/tail const
>> const(*T) indicates tail const
>> const(&T) indicates head const
> 

That's pretty much a horrendous syntax, and I hope I'm not the only to 
think that.

> I think this befuddles the nice clean idea of const(...) as a type 
> constructor that takes the type inside the parens and makes a new 
> const-ified type out of it.
> 
> But fortunately that cleanness can be reclaimed by thinking instead of a 
> _family_ of type constructors, which do head/tail/full const of their 
> argument.  In short, just move the symbol out of the parens so the thing 
> inside the parens remains a valid type.
> 
> const(T) - type constructor making both head/tail const version of T
> const*(T) - type constructor making tail const version of T
> const**(T) - type constructor making tail-of-tail const version of T
> 
> [..and now we're back to what I think was Janice's suggestion many many 
> posts ago, which I liked then too.]
> 

Yes, I like this better too. The '*'s are not mixed the 'T', which is 
better. But like I mentioned in Janice's thread, I think it would be 
even better to have this:

final const(T) - head/tail const
const(T)       - tail const
... and tail-of-tail const would not be supported, at least not with a 
native syntax. I don't see much use for it, so let's keep it simple (but 
should there be a use, such a construct could be made with 
meta-programming anyway).

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D