Files
carbon-lang/docs/design/metaprogramming.md
T
Jon Meow d031f3cdab An incomplete, early, and in-progress overview of the language design. (#83)
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.
2020-07-30 11:37:15 -07:00

928 B

Metaprogramming

Table of contents

TODO

This is a skeletal design, added to support the overview. It should not be treated as accepted by the core team; rather, it is a placeholder until we have more time to examine this detail. Please feel welcome to rewrite and update as appropriate.

See carbon-proposals PR 89 for context -- that proposal may replace this.

Overview

Carbon provides metaprogramming facilities that look similar to regular Carbon code. These are structured, and do not offer inclusion or arbitrary preprocessing of source text such as C/C++ does.