Re: "Macro" expansion

Jonathan, replying to Matt, said:

> >@<object-type|param>:<field-name>[:<index>[:<separator>]]@
> 
> OK, I liked what Matt said, so I went ahead and implemented it. To keep 
> backwards compatibility though, I put in a hack for "package:indexed". 
> I'm not sure where that should fit into your schema Matt.

Hmm... sounds generally good.  I'd probably rip out the
backwards compat stuff at this early stage.

One thing I should pipe up and say: these @<blah>@ "macros"
were initially intended to be a *tiny* shorthand language
just for the most common cases.  For others, you could
write, e.g.:

   <param> !arbitrary-python-expr-here </param>

But maybe what you've got now makes a bit more sense in the
ARK2 world of strings/tables/lists/code/nothing-else.

> I think there is some conceptual horror lying in this
> somewhere that Will will hopefully point out for me...

Yeah, probably :-(  Actually, my bigger concern is to get
this in the documentation.  If you're so inclined, in
ARK/webpages/, either ark-conflang.htma (syntax?) or
field-invoke.htma (semantics?), just bung something in.  I'd
probably change the docstring in ark.utils just to say "go
look over there", so we only have one description.

Check it in -- we're still awfully early in this project.

Will