'Unknown' int/float types actually never exist as such, they get replaced by
type variables immediately. So the whole `Uncertain<IntTy>` thing was
unnecessary and just led to a bunch of match branches that were never hit.
4689: Implement return position impl trait / opaque type support r=matklad a=flodiebold
This is working, but I'm not that happy with how the lowering works. We might need an additional representation between `TypeRef` and `Ty` where names are resolved and `impl Trait` bounds are separated out, but things like inference variables don't exist and `impl Trait` is always represented the same way.
Also note that this doesn't implement correct handling of RPIT *inside* the function (which involves turning the `impl Trait`s into variables and creating obligations for them). That intermediate representation might help there as well.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Co-authored-by: Florian Diebold <florian.diebold@freiheit.com>
This is working, but I'm not that happy with how the lowering works. We might
need an additional representation between `TypeRef` and `Ty` where names are
resolved and `impl Trait` bounds are separated out, but things like inference
variables don't exist and `impl Trait` is always represented the same
way.
Also note that this doesn't implement correct handling of RPIT *inside* the
function (which involves turning the `impl Trait`s into variables and creating
obligations for them). That intermediate representation might help there as
well.
4651: Use first match branch in case of type mismatch, not last r=kjeremy a=flodiebold
The comment says this was intentional, but I do agree with #4304 that it makes
more sense the other way around (for if/else as well).
Fixes#4304.
Co-authored-by: Florian Diebold <florian.diebold@freiheit.com>
4641: Upgrade Chalk r=matklad a=flodiebold
Chalk newly added TypeName::Never and Array; I implemented the conversion for
Never, but not Array since that expects a const argument.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
Function pointers can be 'higher-ranked' over lifetimes, which is why they're
not an application type in Chalk, but since we don't model lifetimes it doesn't
matter for us yet.
4497: Create LowerCtx on the fly r=matklad a=edwin0cheng
Previously we create `LowerCtx` at the beginning of lowering, however, the hygiene content is in fact changing between macro expression expanding.
This PR change it to create the `LowerCtx` on the fly to fix above bug.
However, #4465 is not fixed by this PR, the goto-def is still not work yet. It only fixed the infer part.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>