Arity

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.

Installation

From npm

Install with npx or npm:

# One-shot run, no install:
npx arity-cli format file.R

# Persistent install:
npm install -g arity-cli

The package detects your platform at install time and pulls in a prebuilt binary via npm's optional dependencies --- no Rust toolchain required.

From crates.io

If you have Rust installed:

cargo install arity

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):

[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().