The explorer is an archived codebase, without a plan to restart
development on it. The costs incurred by keeping it in the main git repo
can be alleviated by moving it to a new sibling repo, without
diminishing the usefulness of the explorer codebase for demonstrating
implementation of the carbon language design.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
(Note: this is *not* anything related to April 1st.)
Proposal to switch our week-to-week Carbon project development syncs to
be more
async.
- Start of each week, create a summary of what happened last week.
- Publish this in GitHub discussions for async reading and further
discussion.
- Stop our weekly meeting focused on these summaries.
- Start up a new discussion meetings every two months.
- Structure will be a 10-minutes-or-less update, and a "demo".
- Demo may be traditional: showcase a newly landed thing in Carbon.
- Or demo may showcase an interesting top-of-mind language design
discussion.
- Either way, goal will be to field lots of questions about the topic
and
have a good discussion everyone understands, not to reach some
"conclusion" or "decision".
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Allow qualified name lookup into classes and interfaces as soon as we
reach the `{` of the definition, rather than disallowing such lookups
until we reach the `}`.
Fix destructor syntax ambiguity by switching to `fn destroy` mirroring
standard function syntax. This is a purely syntactic change, maintaining
destructor semantics.
This comes from leads question #4999
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
We propose to add `Core.Array(T, N)` as a library type in the `Core`
package. Since arrays are a very frequent type, we propose to privilege
use of this type by including it in the `prelude` library of the
package.
We would like to see a shorthand where `Core.Array` is automatically
imported into the file scope, and this proposal includes future work to
this effect.
We propose updating our milestones to accelerate design and
implementation of
memory safety in Carbon, and a roadmap for 2025 reflecting this change.
We also
provide a retrospective for 2024's progress.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Introduce a principle that the Carbon language should not encroach on
the
developer's namespace. Satisfy this principle by making `Core` a
keyword.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Proposes a set of core features for declaring and implementing generic
variadic
functions.
A "pack expansion" is a syntactic unit beginning with `...`, which is a
kind of
compile-time loop over sequences called "packs". Packs are initialized
and
referred to using "pack bindings", which are marked with the `each`
keyword at
the point of declaration and the point of use.
The syntax and behavior of a pack expansion depends on its context, and
in some
cases by a keyword following the `...`:
- In a tuple literal expression (such as a function call argument list),
`...`
iteratively evaluates its operand expression, and treats the values as
successive elements of the tuple.
- `...and` and `...or` iteratively evaluate a boolean expression,
combining
the values using `and` and `or`, and ending the loop early if the
underlying
operator short-circuits.
- In a statement context, `...` iteratively executes a statement.
- In a tuple literal pattern (such as a function parameter list), `...`
iteratively matches the elements of the scrutinee tuple. In conjunction
with
pack bindings, this enables functions to take an arbitrary number of
arguments.
---------
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
The prettier pre-commit mirror is no longer supported
(https://github.com/pre-commit/mirrors-prettier). This switches to a
direct call, and updates to 3.3.3. And I'm now specifying types for it
to apply to, rather than letting it ignore unknown files; overall just
trying to separate out which linter sees what.
To comment on formatting changes:
- In most cases, seems to be getting confused by `[]` use in markdown
when it's not part of a link. This looks like a regression, but not one
we're broadly affected by.
- p0107.md - caught an issue with a malformed broken bad link which I've
tried to fix.
- p3720.md - looks like a fix.
Note, prettier has a 4.0.0 alpha release. As best as I could tell, that
only affected the .prettierrc.yaml processing. I changed the glob there
for forwards compatibility.
Establish a process for getting commit access. We will:
- Grant access based on a developer's commit history.
- Someone with commit access should nominate, and a contributor may ask.
- A lead will approve nominations. Only one lead is needed.
- Remove commit access once someone is idle for 6 months.
- "Idle" means no significant project activity on any of GitHub,
Discord,
or in meetings.
- Access removed due to being idle will be restored on request.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Update the operator precedence to achieve a few goals:
- Form operators into groups which behave similarly
- Make the group of operators ("top-level operators") that capture
everything to the right, like `if`...`then`...`else`, behave similarly
to the left, so that rearranging expressions won't change how they
group.
- Add the `where` operator, used to specify constraints on facet types,
to the precedence chart, to define how it interacts with other
operators.
- Make the operator precedence diagram prettier, so that it eventually
can be made into a poster that Carbon programmers can hang on their
walls.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Each entity is restricted to one, optional `extern` declaration. If
used, it must be imported by the defining library. The defining library
annotates the existence of an `extern` with the `has_extern` modifier.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Also a small pass on workflow names.
Note, I'm a little concerned that the test/nightly release/pre-commit
endpoints may be fragile. At the same time, it's also where it may be
most useful, to prevent network access by arbitrary test code. I think
this is imperfect, but maybe we can try it out and see if it's much of
an issue.
Note, the discord wiki action is currently broken, this should fix it.
Proposal for how Carbon version numbers work:
- A single version across language, standard library, compiler, linker,
etc.
- Semantic Versioning (SemVer) based
- Details of how SemVer criteria for major, minor, and patch should
apply to
Carbon
- Details of how we will operate before 1.0 and how this connects to
Carbon's
milestones
- Directional guidance for future work including post-1.0 versions, LTS
versions, and standardization
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
The toolchain's [Semantic IR][semir] should start off modeling the full,
complex, and rich library-based and generic extension point semantics of
Carbon
without eliding any layers or rewrites for compile time efficiency. We
shouldn't
front-load elision or optimization when implementing the designs.
Once we have a full-fidelity implementation, we should work to build an
efficient elision, short-circuit, or common case simplification into the
design
itself sufficient to make the SemIR model efficient. Only if we cannot
find a
reasonable approach for that should we diverge the SemIR model to
optimize its
efficiency, and we should preserve full fidelity in an optional mode.
[semir]:
https://docs.google.com/document/d/1RRYMm42osyqhI2LyjrjockYCutQ5dOf8Abu50kTrkX0/edit?resourcekey=0-kHyqOESbOHmzZphUbtLrTw#heading=h.503m6lfcnmui
---------
Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Require exact syntactic matching in redeclarations. Provide new
terminology for
redeclaration matching and agreement. Specify non-redeclaration rules
for the
other contexts where we require multiple declarations to match, such as
`impl`s
of `interfaces`, `impl`s of `virtual fn`s.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
In order to support exporting imported names, add `export import library
<library>` and `export <name reference>` syntax.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
The usual `pre-commit autoupdate --freeze && pre-commit run -a`
Cutting out a prettier update to v4.0.0-alpha.8 because I'm seeing it
consume all available CPU, basically hanging.
Update broken links to aid in following links while perusing the
documentation. Closes#3778
I don't imagine I got every one of these right. Some 404s may be
reported due to permissions.
Using the lychee command in #3778, only the following link is reported
as not found, but it's just a permission issue:
```
[proposals/p1367.md]:
✗ [404] https://github.com/carbon-language/carbon-lang/settings/access | Failed: Network error: Not Found
```
I tried to get it down to as few as possible, partially so that future
link scans won't run into repeat errors.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
- Add the `extern` keyword for forward declarations in libraries that
don't
provide the definition.
- Treat repeated forward declarations as redundant.
- Allow them when they prevent a dependence on an imported name.
- Clarify rules for when modifier keywords should be on forward
declarations
and definitions.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Add support for extracting elements of a tuple by their numerical index.
Also formally add the well-established basic syntactic and semantic
rules for
tuples, for which we have had leads issues but no proposal, into the
design.
We propose a roadmap for 2024 focused on a working Carbon toolchain that
supports Carbon ↔ C++ interop.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Proposal to focus implementation effort for the next 1-2 years on the
Carbon
toolchain instead of the explorer. This will impact the explorer in a
few ways:
- We will keep the explorer's code in place, building, and passing its
basic
tests. It can remain a good baseline for exploring Carbon's language
features.
- We won't prioritize expanding the explorer's coverage of Carbon
features or
other improvements -- it is good enough for what we need until the
toolchain
catches up.
- We will stop actively fuzzing and expanding test coverage for the
explorer.
- Eventually, when we want to resume work on the explorer, we'll
evaluate the
best platform to build on -- the current explorer codebase or on top of
the
toolchain's semantic IR.
Also tries to update the core readme and contributing docs to reflect
this.
Some background information is at https://bazel.build/external/migration
Trying to handle the simple cases first. This adds a requirement for
bazel 7 due to differences in bzlmod handling between 6 and 7 (also
discussed on
[#infra](https://discord.com/channels/655572317891461132/707150492370862090/1184942191412510720)).
Bazel seems to be okay with a partial migration such as ths.
The python import behavior has subtly shifted, so `carbon.` is no longer
part of import paths. There's a version-incompatible change for `@@`.
bzlmod makes repos sometimes show as `name~version`.
`target-determinator` seems to be okay with `@@` after a version update.
Things not moved here are things that basically need more dep work:
- clang_register_toolchains because I need to dive into its format.
- llvm-project because we need something slightly atypical, I need to
make sure patching and the repo work carries over.
- com_google_libprotobuf_mutator is sufficiently atypical that it
doesn't have a module already, but should be one of the easier things to
fix.
- brotli/woff2: I think we should actually consider removing these. But
again, they're not trivial moves.
- treesitter due to toolchain registration, which has shifted a bit.
- rules_nodejs because treesitter depends on it in an awkward way to
migrate.
The version of `flake8` was too old to support with Python 3.12 -- there
is new F-string support that caused false positives sadly. The updated
version has fixes for all of these.
This in turn updates codespell which has picked up several new fixes
that actually fire in our code, so also fix everything. While we don't
do more in-depth updates to old proposals, similar to simply fixing
broken links, fixing automatically detected typos seems scalable and
fine.
All edits were automatically generated here.
- Require namespace members be declared in the same name scope as the
namespace is declared.
- Allow binding patterns to directly declare names in namespaces.
- Disallow using different namespaces in the same binding pattern.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
When there is no `package` directive, default to `Main//default api`
instead of
`Main//default impl`. This means:
- The extension will be `.carbon`, not `.impl.carbon`.
- There can only be one such file when compiling.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Running `bazel test //...` reported:
```
Test execution time outside of range for MODERATE tests.
Consider setting timeout="short" or size="small".
```
This change adds size="small" to avoid such warnings being reported.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
First step in updating `docs/design/generics/details.md`. It
incorporates changes from proposals: #989#2138#2173#2200#2360#2964#3162 , but there are still more changes from those proposals to be
made.
It also switches away from suggesting static-dispatch witness tables,
and creates an appendix to describe that decision.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Specify the behavior of function calls and the type and behavior of the
entity
introduced by a function declaration.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Change terminology away from terms that are ambiguous:
- Reserve "generic type" for types with (compile-time) parameters, like
`Vector` in `Vector(T:! type)`. Don't use that term to refer to `T`, as
it would with
[#2360](https://github.com/carbon-language/carbon-lang/blob/trunk/proposals/p2360.md#terminology).
- Use the term "compile-time" instead of "constant" to mean "template or
symbolic." Expand the term "constant" to include values, such as from
`let` bindings.
The goal of this proposal is to provide a way for user-defined types to
support range-based iteration with `for`.
The current proposed solution exposes 3 interfaces that can be
implemented by user types to enable support for
ranged-for loops.
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
---------
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
The main motivation for this is to get python loads in using the
`native-py` lint fix. However, enabling that made me wonder, maybe we
should fix in general?
`native-cc` is delayed, but not wholly cancelled (and `native-py`
picking up might indicate `native-cc` won't be too far behind). There's
also some automated fixes for `.append` and dict sorting -- this felt
okay to me, maybe not something to eagerly add but probably not worth
stopping buildifier from fixing (I've noticed the warnings in the past
and had been ignoring them).
Running everything does mean that load orders are sorted automatically
now, which I think is a positive. Most generally, I think these fixes
aren't _harmful_, and having them done automatically seems beneficial:
my biggest concern about `native-py` and `native-cc` was actually that
regressions wouldn't be caught, but this addresses that issue
automatically.
Introduce a concrete design for how Carbon values, objects, storage,
variables,
and pointers will work. This includes fleshing out the design for:
- The expression categories used in Carbon to represent values and
objects,
how they interact, and terminology that anchors on their expression
nature.
- An expression category model for readonly, abstract values that can
efficiently support function inputs.
- A customization system for value expression representations,
especially as
seen on function boundaries in the calling convention.
- An expression category model for references instead of a type system
model.
- How patterns match different expression categories.
- How initialization works in conjunction with function returns.
- Specific pointer syntax, semantics, and library customization
mechanisms.
- A `const` type qualifier for use when the value expression category
system
is too abstracted from the underlying objects in storage.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
Co-authored-by: Adrien Leravat <Pixep@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Dana JansensandJon Ross-Perkins
dongjinlong
cui fliter
Jonathan B. CoeandChandler Carruth
