I hit a roadblock trying to understand linear types, because I couldn't figure out what is meant to "use" a variable. I eventually think I figured it out, by reading "Linear types can change the world!", but it was not easy to do so. I think a better description of what "use" means would be very helpful for those unfamiliar with linear types, so I took a stab at it. Hope it helps.
The Int represented the resolved name, but this isn't guaranteed to be
up to date after reloading and, worse, it doesn't display helpfully. I'm
bored of updating the tests which fail as a result!
This also fixes#407, which is about displaying the wrong name after
reloading the ttc.
This is needed because the existing version won't build the Prelude
correctly as it doesn't do import...as correctly.
I don't believe this affects Idris2-boot, since it has its own Prelude.
There is an argument that, for import public, this should be automatic
(that is, the publicly imported things should be reexported with the
parent namespace). I decided not to do this, because another use of
import public which we do a lot in the Idris 2 code base is purely as a
convenience, where we still expect things to be in their original
namespace.
Also, where there's a choice between things being explicit and implicit,
I prefer to err on the side of explicit now.
So, if what you really want in an API is to reexport, you can do that,
but explicitly.
We only need to reload the defined names so that we can set up the
aliases - everything else is already loaded, and in particular adding
hints twice will break implicit search.
Instead of just the cursory name update that we used to do (which didn't
work properly anyway for a lot of reasons), now we add aliases for all
the names in the imported module.
So, like Idris 1, every global has a canonical name by which we can
refer to it, but it can also have aliases via "import ... as".
The ports are rather straight forward and I have purposefully written
the documentation to be beginner friendly.
Note, I have diverged from Idris1 over the naming of the projection
functions to make them consistent with `Pair` and `DPair`.
The flag takes a natural number as argument
It would be ideal to generalise the argument parser to be able
to parse any argument of any type, but right now we only add
`RequiredNat` as a new flag option.
