Also make minor updates to the skeletal design in
docs/design/name_lookup.md following #2113, as there are no longer any prelude names that are made available to unqualified name lookup by default.
Add `type` to the keyword list in
docs/design/lexical_conventions/words.md, following #2360.
This proposal defines the very basics of `class` types, primarily focused on:
- use cases including: data classes, encapsulated types, inheritance with and without `virtual`, interfaces as base classes, and mixins for code reuse;
- anonymous data types for called _structural data classes_ or _struct types_. Struct literals are used to initialize class values and ad-hoc parameter and return types with named components; and
- future work, including the provisional syntax already in use for features that have not been decided.
The intent is to both make some small incremental progress and get agreement on direction. As such it doesn't include things like nominal types, methods, access control, inheritance, etc.
It proposes this struct type and literal syntax:
```
var p: {.x: Int, .y: Int} = {.x = 0, .y = 1};
```
Note that it uses commas (`,`) between fields instead of semicolons (`;`), and no introducer for types or literal values.
Incorporates decisions from #665 , #653 , #651
Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Adopts new copyright and markdown toc checks.
The new toc check generates the toc header, so that's why all the md files changed (this had felt better to me for the long-term, more auto-generated content)
Co-authored by: chandlerc
- Based on [PR 22](https://github.com/carbon-language/carbon-lang/pull/83)
- [Idea topic](https://forums.carbon-lang.dev/t/proposal-for-an-incomplete-rough-high-level-overview-ready-for-early-feedback/52)
- [RFC](https://forums.carbon-lang.dev/t/rfc-an-incomplete-early-and-in-progress-overview-of-the-language-design/73)
- [Decision announcement](https://forums.carbon-lang.dev/t/accepted-an-incomplete-early-and-in-progress-overview-of-the-language-design/110)
This proposal should be considered a starting point of the language design. It's not intended to be final; language details may change. This is intended to offer a reasonable starting point for:
- Example code.
- Conceptualizing Carbon at a high level.
- Reasonable, but not necessarily final, approaches to features in README.md.
- If any idea is obviously bad, we can clean it up here.
This proposal is not intended to achieve:
- A whole language design.
- This is way too much work for a single proposal; this is a skeletal framework only.
- As we work on feature-specific designs, we may decide to use other approaches. That's fine: we only need somewhere to start.
- The summaries in README.md may be expected to change over time.
- Feature-specific files aren't intended to be well-written or comprehensive. They are a quick jot of prior thoughts.
- We want to avoid getting stuck on language details that we should consider
more carefully regardless. If you're passionate about a feature, please feel
free to start a new proposal for it.
- Each and every aspect of the suggested overview should be subject to careful
examination and justification before it becomes a settled plan of record.
Chandler started this with https://github.com/carbon-language/carbon-lang/pull/22. I've taken it over with the following changes:
- More of a directory hierarchy.
- Trying to thin out the main file (now README.md) to lighter summaries of features.
- Details/rationale/alternatives should be in feature-specific files.
- Draft files are linked as references where added.
For an example of how we may proceed with feature-specific designs, see https://github.com/carbon-language/carbon-lang/pull/80. In this structure:
- docs/design/README.md mentions interoperability, with a light overview.
- The light overview is not yet in https://github.com/carbon-language/carbon-lang/pull/80.
- docs/design/interoperability/README.md goes into more depth on interoperability, covering key points of the approach.
- Individual files in docs/design/interoperability/* go into more depth on interoperability.
Simple designs may not have a subdirectory. All current feature-specific designs do not -- they may be moved later.
Richard Smith
josh11b
Jon MeowandRichard Smith