[Grace-core] RFC: Compile-time constants

[Timothy Jones]

On 03/05, Michael Homer wrote:
> On Sat, May 3, 2014 at 12:43 AM, Timothy Jones <tim at ecs.vuw.ac.nz> wrote:
> > On 02/05, Michael Homer wrote:
> >> It seems like these are what you want for inheritance ("definitively
> >> static") too, so it's worth factoring in what that needs as well.
> >
> > I disagree (with the spec, I suppose) that this should even be a thing. An
> > invalid inheritance chain should be a runtime error. If a dialect wants to check
> > this (as the type checking dialect should) then it can, and in that context
> > "definitively static" means whatever the dialect wants it to mean (presumably
> > whether it can see the definition site).
> Where does identifier resolution occur in this system?

Runtime, at the call site. I understand that the C compilation prevents this
from happening though.

> >> - Can it be inherited?
> >
> > No, for similar reasons as 'let'.
> Hang on, I can see how there's a case for lets to be top-level-only,
> but methods? How is this code:
>   method foo {
>     object {
>       method x is public, static { 1 }
>       let y = x + 1
>     }
>   }
>   object {
>     inherits foo
>    }.x
> ?

I'm not sure what you're asking here. I answered this as 'can it be overriden',
so we might be on a different page here.

> On the other hand, if it can be inherited, can it refer to self?

If self is static, I guess.

> >> - What is it allowed to return?
> >
> > A request for another static value, or a fresh object (like a brand -- this is
> > why you can annotate a class as static).
> These are a lot like the inheritance rules.
> 
> Can you inherit from a static method?

Do you mean if the inheriting object is also static?

-- 
Tim