Includes support for the `impls`, `=`, and `==` requirement operators to
the right of a `where`, but `and` to allow multiple requirements is
still a TODO.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Parse the name of a declaration as a sequence of `NameQualifier`s --
which have a name, possibly parameters, and a trailing period --
followed by a name and possibly parameters. This prepares us for parsing
declarations of members of generic classes and similar cases, but
actually supporting such member redeclarations is left to a future
change.
We previously required functions to have parameters, but no longer do,
following the direction of #3848. Cases like namespaces that can't
actually have parameters are now diagnosed in check instead of in parse.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Change syntax for package declaration to put the `impl` keyword at the
start and remove the `api` keyword.
To support this, rearrange processing of package, library, and import
declarations to use the general modifier handling support in declaration
parsing rather than special-case logic.
There is an ambiguity in `impl package.Foo as Bar`, which we resolve by
treating `package` as an introducer after a modifier only if it's not
followed by `.`.
This provides `export import` logic in lex, parse, and check; `export
name` logic is only in lex and parse, not check.
I think with `export name` I'm going to need to modify import_ref and
some consolidation logic, whereas `export import` seems feasible to keep
as primarily import logic. Given the implementations were looking like
they'd diverge more substantially, I thought it'd be helpful to cut the
PR here.
Noticed an unexpected format change in #3850, it's probably because
pre-commit needs to explicitly include def files. The def change here is
a consequence of `pre-commit run -a` with this change.
On the parsing side, we treat `a.(b)` as a member access whose second
operand is a `ParenExpr` rather than a `MemberName`. A new node category
is added for the union of `MemberName` and `ParenExpr` to support this.
Checking is mostly reusing the same pieces we already have for simple
member access. Compound member access is in most ways a simplified form
of simple member access because it doesn't need to do any lookup.
This undoes parts of #3515 in order to allow PushGlobalInit to be called
when the initializer is called, instead of at the end of the binding
pattern. The current approach is fragile because supported patterns will
become more complex. We also will likely want similar support in `let`,
which puts the initializer first, so this offers a consistent approach
for both.
[Looking
back](https://discord.com/channels/655572317891461132/655578254970716160/1184237511766179840),
this is more or less the second option in that message, but using the
PeekNextIs to avoid vagueness about what's being popped first.
Note I'm putting in PeekNextIs for what I'm hoping will be a pretty
narrow use-case. I could've added depth arguments to the Peek functions,
but that would've rippled through a number of APIs and it's not clear to
me that this has generic utility. I mean, right now it could just be
PeekNextIsVariableInitializer, since it's only optional in that case.
Adds `BindAlias` with a hybrid of `BindName` and `NameRef` semantics. I
think it's slightly closer to `BindName` because it introduces a name,
so I'm going more in that direction. This also matches the need for
`bind_name_id` with imports on enclosing scopes.
Note, only things that look like a name reference are being allowed on
the RHS of `alias`. This includes builtins that look like name
references, such as `bool`, but not ones that turn into values
underneath, such as `false`.
Also stop supporting `var` with initializer inside `for`.
Resolves TODO in `handle_variable.cpp`
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This leaves a single state for each in the expr loop. I was trying to
think through ways to have per-token states, but they felt sort of
bulky.
Note this is more verbose: but I think the long-term is going to be that
when we start wanting to add handlers, we're going to need to switch to
different names based on the token found. As a consequence, the parse
state logic will end up diverging a little, and we'll just want to align
towards boilerplate handlers.
Short-term, this opens up a path for saying that each parse node
corresponds to precisely one token in success states, and separates out
what were becoming big handler functions in check.
This is also doing the parse node split, allowing lower reliance in
formatter on the tokenized buffer (something that I may be touching more
due to import handling).
(Split out of #3410)
Consistently use `ParenExpr` solely for parenthesized single
expressions, and use more syntax-oriented terminology for states and
nodes that might represent either a `ParenExpr` or a tuple literal.
Building on #3463. The PushState+PopState to construct a state feels
worth cleanup. The rest is just kind of making it easier to do without
adding another PushState overload.
This should cover:
```
library "lib" api;
import Foo library default;
import library default;
import library "lib";
```
This splits out `PackageName` and `LibraryName` to their own parse nodes
so that checking can ignore them and still get a balanced parse tree
(otherwise, we essentially need to implement handling of the parse nodes
only to remove the identifiers/string literals -- the optional names
mean we can't blindly do that as before). For reference, these nodes
don't need to be handled because CheckParseTree will need to directly
funnel import information along with checked IRs.
For now, we require the same introducer to be used each time a class is
declared, but see #3384.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Implement toolchain support for `returned var` and `return var`.
- Modeled `returned` in the parse tree as a `ReturnedSpecifier`
appearing after the `VariableIntroducer`.
- Modeled `return var` in the parse tree as a `ReturnVarSpecifier`
appearing after the `ReturnStatementStart`.
- Factored out the implementation of `return` statement and `returned
var` handling in check into a new `return.{h,cpp}`. The parse nodes
themselves are still handled in `handle_*.cpp`. This allows easy code
reuse between `return` and `returned var`.
This detects ordering issues with the `package` and `import` statements.
`library` is changed from package-specific to instead be generic between
the two, since structurally it's non-specific.
The next step would be to start exposing the results for the driver to
make ordering decisions for checking. That'll involve further
modifications to this code, but this felt like a reasonable change point
because it's the extent of the parser enforcement, and still causes
significant refactoring.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
A `let` declaration is represented by a `bind_name` node in SemIR:
```carbon-semir
%b: i32 = bind_name "b", %a
```
Because `Check` encounters the pattern before it sees the value, we
first create the `bind_name` node with an unset value and don't add it
to the block. Then, once we've seen and converted the initializer, we
update the `bind_name` to have the value and add it to the current
block, after the initializer code.
Continuing with #3070. Just a dir and file rename (mostly removing
prefixes, although for parse_tree_fuzzer and parse_tree_file_test I'm
dropping "tree" instead of "parse"). Everything in the parse dir should
be marked as a move.