[Grace-core] Inheritance and Template Objects

[Andrew P. Black]

On 3 Apr 2013, at 18:28, James Noble wrote:

> not sure here. I'll accept it for now, but if they really were nominal, I think it breaks your interval example as the two templates would have different nominal types.  But I think I know what you mean - perhaps something like singleton types?? - which is fine.

What I meant was: the only templates are those generated by the template mechanism in the language.   I can't cons up a new object out of whole cloth and have it be a template, even if it does have all of the right methods.   Maybe "branded" is a better word.

If you plan to use template types to do type inference, then 

	template { method a -> Number ; method b -> Done }

better have the same type as

	template  template { method a -> Number } + template { method b -> Done }

I thought of doing this using flow analysis and constant propagation, rather than type checking, but I can see that you could use type checking.

> 	myObject.template or mirrors.templateOf(Object)
> 
> do you think of this as as base-level operation or a metal-level operation -
> 

Getting a template from an object is clearly a meta-level operation.   But then, so is inheritance.   So I think that's OK.

	Andrew
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