Per #3714, some of the details here are not yet settled. In particular,
we might want `Self` to come into scope at the start of the definition,
not at the `as` keyword. However, this change allows us to accept the
uncontroversial examples.
This was previously discussed at
https://discord.com/channels/655572317891461132/655578254970716160/1209975051588210729.
I'm initiating this mainly because we typically use "id" suffixes to
indicate an `IdBase` being passed around and the non-id suffix of
`parse_node` suggests at it carrying more data than it actually does.
There used to be more reason for avoiding `node_id` because
`SemIR::InstId` used to be named `NodeId`, but that's no longer
necessary. As a consequence, I'd like to rename `parse_node` to more
precisely reflect its type.
In full, this is doing:
```
parse_node_kind -> node_kind
parse_node -> node_id
ParseNodeCategory -> NodeCategory
ParseNodeKind -> NodeKind
ParseNode -> NodeId
```
This is primarily in check and sem_ir, but with some `parse_node_kind`
references in parse too.
Pluralization is consistent with name forms on both sides, so that
wasn't part of my replacements.
This doesn't add full support. I'm separating it out to make the effects
of the modifier changes clearer for review. I'm restructuring a little
with the expectation that we'll have some more categories of modifier
keywords in the future (similar to `extern`, these may not be in a "set"
such as access), and thus easily scaling up to a few more would be
useful.
Add an instruction to hold the witness table, along with a corresponding
type to keep things simpler. Add `check/impl.{h,cpp}` to house the new
logic. No checking of impls against interfaces is performed yet.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Interface support is pretty skeletal so this may need additions later,
but I think it's still worthwhile to fill in the necessary bits now.
With this change, the expectation is then that everything we have right
now which _can_ be imported, is supported for import (at least for the
"current package, no overlap" case).
To make the implementation simpler, make `PopWithParseNodeIf` return
`pair<NodeId, optional<value>>` rather than `optional<pair<NodeId,
value>>`. While wrapping the whole result in `optional` seems more
principled, it's significantly harder to work with.
Note we may also want to do this with NameId, maybe some other things,
but the TypeId use is pretty broad and repetitive -- I thought I'd start
with it first.
They don't have names, but using the DeclNameStack anyway keeps our
behavior more consistent, and keeps track of the enclosing name scope
and the prior state of the scope stack for us.
Depends on #3683.
Collect the contents of an `impl` into a scope, and start doing very
basic checking for `impl` declarations and definitions.
This change adds two new `Id` types to the set of type that `NodeStack`
supports -- `ImplId` and `NameScopeId`.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Use two different nodes for "<type> followed by `as`" and "<type>
omitted before `as`, use `self`", so it is easier to determine which
case. Later the second case will push the type id for `self` onto the
node stack, making the two paths more similar.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Consume the components of the `impl` declaration, and set up scopes for
the child elements. We don't yet build a representation for the impl
itself.
Also, add an interface type value. This is necessary so that we have a
value for the expression on the right-hand side of `as` in an `impl`.
Goal is to increase type safety, though more work needs to be done (see
added TODOs).
Note that, after this change, check handlers corresponding to deleted
parse node kinds will no longer compile.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>