first attempt at making hdata less annoying

hdata_test.lua

w, script_name = weechat, "hdata_test"

hdata = {
   meta = {
      __index = function (tb, name)
         local var_type = tb._vars[name]
         if not var_type then
            return
         end
         if var_type == "hashtable" then
            return w.hdata_hashtable(tb._hdata, tb._ptr, name)
         elseif var_type:sub(1, 1) == "@" then
            return hdata.new(var_type:sub(2), w.hdata_pointer(tb._hdata, tb._ptr, name))
         else
            local func = w["hdata_"..var_type]
            local size = w.hdata_get_var_array_size(tb._hdata, tb._ptr, name)
            if size < 1 then
               return func(tb._hdata, tb._ptr, name)
            end
            local v = {}
            for i = 0, size - 1 do
               v[#v+1] = func(tb._hdata, tb._ptr, i.."|"..name)
            end
            return v
         end
      end
   },

   new = function (name, ptr)
      if not name or not ptr or name == "" or ptr == "" then
         return nil, "hdata name and pointer can not be empty"
      end
      local tb = {
         _type = name,
         _ptr = ptr,
         _hdata = w.hdata_get(name),
         _vars = {}
      }
      if tb._hdata == "" then
         return nil, "unknown hdata: "..name
      end
      local var_keys = w.hdata_get_string(tb._hdata, "var_keys")
      for var_name in var_keys:gmatch("([^,]+)") do
         local var_type = w.hdata_get_var_type_string(tb._hdata, var_name)
         if var_type == "shared_string" then
            var_type = "string"
         elseif var_type == "pointer" then
            local var_hdata = w.hdata_get_var_hdata(tb._hdata, var_name)
            if var_hdata ~= "" then
               var_type = "@"..var_hdata
            end
         end
         tb._vars[var_name] = var_type
      end
      return setmetatable(tb, hdata.meta)
   end,

   list = function (name, list_name)
      return hdata.new(name, w.hdata_get_list(w.hdata_get(name), list_name))
   end
}

function main()
   w.register(script_name, "singalaut <https://github.com/tomoe-mami>", "0.1", "WTFPL", "hdata test", "", "")
   local server = hdata.list("irc_server", "irc_servers")
   while server do
      w.print("", server.name)
      if server.is_connected == 1 then
         local channel = server.channels
         while channel do
            w.print("", "    "..channel.name)
            channel = channel.next_channel
         end
      end
      server = server.next_server
   end
end

main()