feat(sources): added support for loading external sources

lua/trouble/sources/init.lua

@@ -0,0 +1,63 @@
+local Config = require("trouble.config")
+local Util = require("trouble.util")
+
+---@class trouble.Source
+---@field highlights? table<string, string>
+---@field config? trouble.Config
+---@field setup? fun()
+---@field get trouble.Source.get|table<string, trouble.Source.get>
+
+---@alias trouble.Source.ctx {main: trouble.Main, opts:trouble.Mode}
+---@alias trouble.Source.Callback fun(items:trouble.Item[])
+---@alias trouble.Source.get fun(cb:trouble.Source.Callback, ctx:trouble.Source.ctx)
+
+local M = {}
+---@type table<string, trouble.Source>
+M.sources = {}
+
+---@param name string
+---@param source? trouble.Source
+function M.register(name, source)
+  if M.sources[name] then
+    error("source already registered: " .. name)
+  end
+  source = source or require("trouble.sources." .. name)
+  if source then
+    if source.setup then
+      source.setup()
+    end
+    require("trouble.config.highlights").source(name, source.highlights)
+    if source.config then
+      Config.defaults(source.config)
+    end
+  end
+  M.sources[name] = source
+  return source
+end
+
+---@param source string
+function M.get(source)
+  local parent, child = source:match("^(.-)%.(.*)$")
+  source = parent or source
+  local s = M.sources[source] or M.register(source)
+  if child and type(s.get) ~= "table" then
+    error("source does not support sub-sources: " .. source)
+  elseif child and type(s.get[child]) ~= "function" then
+    error("source does not support sub-source: " .. source .. "." .. child)
+  end
+  return child and s.get[child] or s.get
+end
+
+function M.load()
+  local rtp = vim.api.nvim_get_runtime_file("lua/trouble/sources/*.lua", true)
+  for _, file in ipairs(rtp) do
+    local name = file:match("lua/trouble/sources/(.*)%.lua")
+    if name and name ~= "init" and not M.sources[name] and package.loaded["trouble.sources." .. name] == nil then
+      Util.try(function()
+        M.register(name)
+      end, { msg = "Error loading source: " .. name })
+    end
+  end
+end
+
+return M