Neovim Editor integration for Piglet, currently contains:

• Conjure Piglet client
• pdp, a Piglet Dev Protocol server implementation, for interactive eval
• setup Neovim Piglet filetype.
• register Piglet into Conjure.

Setup

1. Prepare the required luarocks dependencies. (See next section)
2. Config init.vim with following content and then :PlugInstall

" install with vim-plug
call plug#begin(stdpath('data') . '/plugged')
...
Plug 'humorless/conjure-client-piglet'
...
call plug#end()


" register piglet filetype into Neovim/Conjure
" and register conjure-client-piglet for piglet filetype
lua require("conjure-client-piglet").setup()

Requirements

 luarocks install org.conman.cbor
 luarocks install lua-websockets 

Install/configure luarocks with Neovim

If we install lua-cbor using Luarocks, can we use it in Lua scripts inside Neovim?

The answer is not by default — some adjustments are needed.

This is because our Luarocks was also installed via Homebrew, and the default Lua interpreter used by Luarocks differs from the one Neovim uses by default. Additionally, Neovim's package path likely won’t include Luarocks' installation paths.

Solution A:

Use rocks.nvim or luarocks.nvim to manage it.

Solution B:

1. Reinstall Luarocks

Download the source tarball, recompile, and install it so that it links explicitly to the same Lua interpreter used by Neovim — namely, LuaJIT.

2. Configure Neovim’s internal package.path and package.cpath

This ensures that Neovim can locate the modules and shared libraries installed via Luarocks.

Reinstall Luarocks — Step-by-step:

$ brew install luajit
$ wget https://luarocks.org/releases/luarocks-3.12.0.tar.gz
$ tar zxvf luarocks-3.12.0.tar.gz && cd luarocks-3.12.0
$ mkdir ~/.luarocks-luajit
$ ./configure \
  --with-lua=$(brew --prefix luajit) \
  --with-lua-include=$(brew --prefix luajit)/include/luajit-2.1 \
  --lua-suffix=jit \
  --prefix=$HOME/.luarocks-luajit
$ make && make install

Note: The version of Luarocks is important. LuaJIT has a limit of 65536 constants in a single function. If you don’t use a compatible version of Luarocks, you may encounter the error:

Error: main function has more than 65536 constants

(See related references for more.)

Configure Neovim with Luarocks Modules

1. Under your Neovim lua/ directory, create a file named luarocks.lua.

2. Paste the following content into it, and replace the $username variable.

local function add_luarocks_paths()
local luarocks_path = "/Users/$username/.luarocks-luajit/share/lua/5.1/?.lua;/Users/$username/.luarocks-luajit/share/lua/5.1/?/init.lua"
local luarocks_cpath = "/Users/$username/.luarocks-luajit/lib/lua/5.1/?.so"
package.path = package.path .. ";" .. luarocks_path
package.cpath = package.cpath .. ";" .. luarocks_cpath
end
return { add_luarocks_paths = add_luarocks_paths }

3. In your init.vim, add the following line:

lua require("luarocks").add_luarocks_paths()

Dev

Swith on debugging: add the following lines to init.vim:

let g:conjure#debug = v:true

Reusable Part: Lua websockets for Neovim

conjure-client-piglet/server_uv.lua is adapted from server_ev.lua in lua-websockets.
I removed its original dependency on LuaSocket and replaced it with a dependency on vim.uv’s TCP socket.

While developing this part, I spent some time searching but couldn’t find a Lua WebSocket implementation suitable for Neovim, so I modified one myself.