# Brine

> Brine is a compiled systems language with Python-like syntax. The compiler proves contracts and array bounds at compile time, data races and distributed deadlocks are compile errors, `par` constructs run on every core or the GPU, and parallel reductions give the same bits on every machine.

Key facts for writing Brine:

- Blocks use `:` and 4-space indentation, like Python. Files end in `.br`.
- `let` is immutable, `var` is mutable. No implicit numeric conversions.
- Values are copied (copy-on-write); `ref` parameters change the caller's variable and the caller writes `f(ref x)`.
- `requires`, `ensures`, `invariant` and `prove` must be proven at compile time; `assert` checks at runtime and becomes a fact.
- Inside `par for i in ...`, outer arrays may only be written at `[i]`.
- Run `brine check` after every edit; add `--json` for machine-readable diagnostics; `brine explain <CODE>` explains any error.
- Every page of these docs is also available as Markdown: add `.md` to its URL.

## Documentation Sets

- [Abridged documentation](https://docs.brinelang.org/llms-small.txt): a compact version of the documentation for Brine, with non-essential content removed
- [Complete documentation](https://docs.brinelang.org/llms-full.txt): the full documentation for Brine
- [Language](https://docs.brinelang.org/_llms-txt/language.txt): syntax, types and the standard built-ins
- [Parallelism](https://docs.brinelang.org/_llms-txt/parallelism.txt): par constructs, GPUs and the world module
- [Proofs](https://docs.brinelang.org/_llms-txt/proofs.txt): contracts, the prover and runtime checks

## Notes

- The complete documentation includes all content from the official documentation
- The content is automatically generated from the same source as the official documentation