The current system with AstIds has two primaraly drawbacks:
* It is possible to manufacture IDs out of thin air.
For example, it's possible to create IDs for items which are not
considered in CrateDefMap due to cfg. Or it is possible to mixup
structs and unions, because they share ID space.
* Getting the ID of a parent requires a secondary index.
Instead, the plan is to pursue the more traditional approach, where
each items stores the id of the parent declaration. This makes
`FromSource` more awkward, but also more correct: now, to get from an
AST to HIR, we first do this recursively for the parent item, and the
just search the children of the parent for the matching def
This commit implements a general truncation framework for HirFormatter
that keeps track of how much has been output so far. This information
can then be used to perform truncation inside the language server,
instead of relying on the client.
Initial support is implemented for truncating types hints using the
maxInlayHintLength server config option. The existing solution in the
VSCode extension has been removed in favor of letting the server
truncate type hints.
We need to be more careful now when substituting bound variables (previously, we
didn't have anything that used bound variables except Chalk, so it was not a
problem).
This is obviously quite ad-hoc; Chalk has more infrastructure for handling this
in a principled way, which we maybe should adopt.
2200: Add variables to HIR r=matklad a=matklad
Introduce a `hir::Variable`, which should cover locals, parameters and `self`. Unlike `PatId`, variable knows it's owner so it is self-contained, and should be more convenient to use from `ra_ide_api`.
The goal here is to hide more details about `Body` from hir, which should make it easier to move `Body` into `hir_def`. I don't think that `ra_ide_api` intrracts with bodies directly at the moment anyway, but the glue layer is based basically on `ast::BindPat`, which seems pretty brittle.
Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
