Lua REPL console for Hyprland

repl.lua

-- Lua UDP REPL console for Hyprland
-- Just stick repl.lua in .config/hypr and `require "repl"`
-- Connect with `socat readline,prompt="> " udp-datagram:localhost:42069`
-- Get luasocket somehow, `pacman -S lua-socket` installs here:
package.path = "/usr/share/lua/" .. _VERSION:sub(5) .. "/?.lua;/usr/share/lua/" .. _VERSION:sub(5) .. "/?/init.lua;" .. package.path

-- lua-inspect is on e.g. aur
-- Pretty useful, not really required, so lets not error on that, although hl custom error handler might do it anyway
_, inspect = pcall(require, "inspect")

local socket = require("socket")
local udp = assert(socket.udp())
local function listen()
  udp:setoption("reuseaddr", true)
  udp:setoption("reuseport", true)
  udp:setsockname("*", 42069)
  udp:settimeout(0)
  while true do
    local msg, ip, port = udp:receivefrom()
    if msg then
      if msg:sub(1, 7) ~= "return " then msg = "return " .. msg end
      local f, e = load(msg)
      if f then
        local s, r = pcall(f)
        if s then
          udp:sendto(tostring(r) .. "\n", ip, port)
        else
          udp:sendto("Error: " .. tostring(r) .. "\n", ip, port)
        end
      end
    end
    coroutine.yield()
  end
end

hl.timer(function()
  if not repl_thread then
    repl_thread = coroutine.create(listen)
  end
  if repl_thread then
    local s, e = coroutine.resume(repl_thread)
    if coroutine.status(repl_thread) == "dead" then
      repl_thread = coroutine.create(listen)
    end
  end
end, { timeout = 16, type = "repeat" })