---
title: lang
related:
  - "[nvim-lu](nvim-lu.md)"
  - "[yaci](yaci.md)"
categories:
  - Languages and compilers
---

**lang** is the home of **Lu**, a programming language I'm designing, and its
compiler. The main repository is on
[Codeberg](https://codeberg.org/hugocoto/lang); GitHub has a mirror.

> [!NOTE]
> Work in progress. Sorry, I like macros.

## A taste of Lu

```
extern printf: int => int;
intern print_num: int => int;

0 -> (i: int) => { i -> print_num };
```

Values flow left to right through `->` into functions (`x -> f`). Functions
are lambdas (`(a: Int) => { ... }`), and a block of LLVM IR can be written
inline to define a function. The design sketches in the repository
(`hello*.lang`) also explore tagged unions, typed lists and maps, and
multiple assignment.

## Repository layout

| Path | Contents |
|---|---|
| `compiler/` | The compiler, with example `.lu` programs |
| `docs/` | Documentation, in Typst |
| `damerau_levenshtein.c` | Suggests the closest word from a list; meant for compiler error hints |
| `hello*.lang` | Snippets used to model the language (6 is the best) |

## See also

- [Codeberg repository](https://codeberg.org/hugocoto/lang)
- [GitHub mirror](https://github.com/hugoocoto/lang) (zlib)
- [nvim-lu](nvim-lu.md): syntax highlighting for Neovim