Enhace: add a faster fallback for lualine_require for requiring files out of repo

If that fails it still falls back to original require a last resort

lua/lualine/utils/loader.lua

@@ -8,7 +8,7 @@ local modules = lualine_require.lazy_require{
 }
 local is_valid_filename = lualine_require.is_valid_filename
 
-local sep = package.config:sub(1,1)
+local sep = lualine_require.sep
 
 local component_types = {
   luaf = function(component)
@@ -132,20 +132,11 @@ local function load_all(config)
   load_extensions(config)
 end
 
-local function rtp_searcher(file)
-  local ret = {}
-  for dir in vim.gsplit(vim.api.nvim_get_option('rtp'), ',') do
-    local path = dir .. sep .. file
-    if vim.loop.fs_stat(path) then ret[#ret+1] = path end
-  end
-  return ret
-end
-
 local function load_theme(theme_name)
   assert(is_valid_filename(theme_name), "Invalid filename")
   local retval
   local path = table.concat({'lua', 'lualine', 'themes', theme_name}, sep)..'.lua'
-  local files = rtp_searcher(path)
+  local files = lualine_require.rtp_searcher(path)
   local n_files = #files
   if n_files == 0 then
     -- No match found

lua/lualine_require.lua

@@ -18,8 +18,9 @@ end
 
 function M.require(module)
   if package.loaded[module] then return package.loaded[module] end
+  local pattern = module:gsub('%.', M.sep) .. '.lua'
   if M.plugin_dir then
-    local path = M.plugin_dir .. module:gsub('%.', M.sep) .. '.lua'
+    local path = M.plugin_dir .. pattern
     assert(M.is_valid_filename(module), "Invalid filename")
     if vim.loop.fs_stat(path) then
       local mod_result = dofile(path)
@@ -27,9 +28,29 @@ function M.require(module)
       return mod_result
     end
   end
+
+  local paths = M.rtp_searcher('lua'..M.sep..pattern, true)
+  if #paths > 0 then
+    local mod_result = dofile(paths[1])
+    package.loaded[module] = mod_result
+    return mod_result
+  end
+
   return require(module)
 end
 
+function M.rtp_searcher(file, once)
+  local ret = {}
+  for dir in vim.gsplit(vim.api.nvim_get_option('rtp'), ',') do
+    local path = dir .. M.sep .. file
+    if vim.loop.fs_stat(path) then
+      ret[#ret+1] = path
+      if once then break end
+    end
+  end
+  return ret
+end
+
 function M.lazy_require(modules)
   return setmetatable({}, {
     __index = function(self, key)