# Arity <img src='https://raw.githubusercontent.com/jolars/arity/refs/heads/main/images/logo.svg' align="right" width="139" />
Arity is a language server, formatter, and linter for the R programming
language. It is designed to provide a seamless development experience for R
programmers by integrating with popular code editors and IDEs.
## Formatter
To format your code, you can use:
- `arity format [file]`
- `arity format --verify [file]`
- `arity format --check <path> [<path> ...]`
## Linter
To lint your code, you can use:
- `arity lint --check <path> [<path> ...]`
## Editor integration
`arity lsp` starts a stdio-based language server. It currently advertises only
formatting (`textDocument/formatting`); diagnostics and other capabilities are
not implemented yet. Configuration is read from `arity.toml` discovered from
each file's parent directory, matching the CLI.
Helix example (`~/.config/helix/languages.toml`):
```toml
[language-server.arity]
command = "arity"
args = ["lsp"]
[[language]]
name = "r"
language-servers = ["arity"]
formatter = { command = "arity", args = ["format"] }
```
Neovim (with `nvim-lspconfig` or a custom client) should launch `arity lsp` for
files with the `r` filetype and request formatting via `vim.lsp.buf.format()`.