Italian Swirls 🍝

Minimal Python language server, based on Jedi and pygls.

It works on the subset of versions supported by both Jedi and pygls, so in its current set of dependencies:

• Python 3.8 at least
• Python 3.12 at most

Supported features:

LSP method	Description
textDocument/completion	Complete
textDocument/definition	Go to definition
textDocument/typeDefinition	Go to type definition
textDocument/hover	Show documentation
textDocument/references	Show references
textDocument/rename	Renaming symbols and files

Install

You can either clone and build the server package from this repository, or install it from PyPI:

pip install italianswirls

The only dependencies are pygls and Jedi.

Because Jedi is able to detect which environment it is installed in and which environment is the project you're working on in, you do not need to install in every virtualenv where it might be handy; a global user (or root) installation should be sufficient to work regardless of your current virtualenv.

Refer to your client documentation on how to setup a server. Yes I have no idea how to do it for your editor, except if it's Neovim and you use nvim-lspconfig, then you can add something like that to your init:

require('lspconfig.configs').italianswirls = {
  default_config = {
    cmd = { 'italianswirls' },
    filetypes = { 'python' },
    root_dir = require('lspconfig.util').root_pattern(
      unpack({ 'pyproject.toml', 'setup.cfg' })
    ),
    single_file_support = true,
  },
  docs = {
    description = "“Is this a Star Wars reference?” Language Server",
    default_config = {
      root_dir = "vim's starting directory",
    },
  },
}

-- using a previously defined on_attach function…
lspconfig.italianswirls.setup { on_attach = on_attach }

Development

The project uses Poetry for dependency management and packaging.

poetry install            # install deps in a virtualenv
poetry run italianswirls  # run the LS but it may be impractical to test
poetry build              # build to wheel

About

Why?

General-purpose servers (e.g. pyls, py-lsp) try to do too much and break stuff too often for me. Locking Neovim when I press tab, crashes of all kind, LspRestart failing. Also I like my linting and formatting done by dedicated tools such as nvim-lint and Conform.

Other Jedi-based servers (e.g. jedi-language-server) seem to focus on coc-nvim and frequently fail on Neovim's native LSP client for me. I tried to fix jedi-language-server several times when it failed me but I thought it could be fun to try pygls to redo it as small and simple as I can. And running a Node server to get Python completions? No way. That said, jedi-language-server is a good project and if you're fine with coc-nvim you should definitely check it out. Lots of the code here is stolen inspired from this project.

Is it usable for me?

Try it. It was a small project for my own usage but it's been surprisingly reliable over the years now. That said, I do not program in Python professionally since some times now so I do not have the same strict requirements as before regarding to my tools.

Why the name?

Take the string “Is this a Star Wars reference?” Language Server, compress it to ITASWRLS and expand it back to Italian Swirls. Italian dishes are made of few elements that work well together. Enough questions!

License

GPLv3.