[Grace-core] Some comments from Tijs on parsing Grace

[James Noble]

> It’s simple.  If you want explicit type parameters, you put them in, using the ordinary parameter syntax and specifying that their type is Type.  If you don’t want explicit type parameters, you do what is shown in the pdf extract .

ahh OK, yep.   I did remember you telling me that, the excerpt from the manual 
didn't cover it that's all

> In Emerald, the number of arguments must always be the same as the number of parameters.  There are no defaults.

other than these "implicits",  But Emerald wasn't "gradually typed".


On reflection - I wonder if I was (somewhat) confusing things in my last comments.  There is a (big) difference between a dialect inferring types or type parameters and using them (locally, statically) to check things. and the 
dialect (if it could) or core compiler (which can)  using inference to 
(globally, dynamically) populate the reified generic parameters. 

The catch is that if these two things are different we're back to Java generic erasure, basically.   

This is tricky, and I don't think we've thought through it enough.
I fear no-one has.   We should ask Jeremy & Ron again.

james