Adds the following information about name resolution to the trace
output:
* Name resolution process
```
** resolving stmt | decl `<stmt | decl>` (<source_location>)
...
** finished resolving stmt | decl `<stmt | decl>` (<source_location>)
```
* When a name is added to the static scope
```
--- declared `<name>` as `<entity>` in `<scope>` (<source_location>)
```
* When a name is resolved
```
--- resolved `<name>` as `<result>` in `<scope>` (<source_location>)
```
* Marking a name declared/usable
```
--- marked `<name>` <usable | declared but not usable> in `<scope>`
```
First step towards permitting declarations within namespaces. Supports only functions within namespaces for now, with no way to call those functions except from within other such functions. Unqualified lookups within a function in a namespace look in that namespace first.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Instead of complaining that the name is not completely declared, say it's not
declared at all yet.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This PR implements the `returned var` for the explorer.
- Enabled `returned var` and `return var` syntax in lexer and parser.
- Split `Return` statement into `ReturnVar` and `ReturnExpression` to distinguish the two types of returns.
- Added logic in name resolution, type checking and interpretation to process `returned var` definition and `ReturnVar` statement.
`.Self` is modeled as a new kind of expression, `DotSelfExpression`. Name resolution associates each occurrence of a `DotSelfExpression` with a generic binding, much like for an `IdentifierExpression`.
Both `:!` bindings and `where` expressions bring `.Self` into scope. The tentative intent is that if there are multiple `.Self`s in scope and they refer to different bindings, the result of using a `.Self` expression is an ambiguity error, but that is not implemented in this patch. Instead, like for `IdentifierExpression`s, we find the innermost enclosing definition of `.Self`.
`.Foo` expressions are rewritten to `.Self.Foo`, but this isn't enough to make them do anything useful, because associated constants aren't supported in general yet.
Jon Ross-Perkins
Prabhat Sachdeva
Richard Smith
SlaterLatiao
pk19604014