How would one make os.loadAPI() in pure Lua?

function love.load()
function customParse(parseString, parseCharacter)
		local parseResults = {}
		local stringCycle = ""
		for i = 1, #parseString do
		 local c = parseString:sub(i,i)
		 if c == parseCharacter then
				if stringCycle == "" then
				else
					table.insert(parseResults, stringCycle)
					stringCycle = ""
				end
		 else
				stringCycle = stringCycle .. c
		 end

		 if i == #parseString and c ~= parseCharacter then
				table.insert(parseResults, stringCycle)
				stringCycle = ""
		 end
	 end
	return parseResults
end
tAPIsLoading = {}
function loadAPI(_sPath)
  customParsedPath = customParse(_sPath, "/")
  local sName = customParsedPath[#customParsedPath]
  if tAPIsLoading[sName] == true then
   error("API " ..sName.." is already being loaded")
   return false
  end
  tAPIsLoading[sName] = true
  local tEnv = {}
  setmetatable(tEnv, {__index = _G})
  local fnAPI, err = loadfile(_sPath, tEnv)
  if fnAPI then
   local ok, err = pcall(fnAPI)
   if not ok then
	error(err)
	tAPIsLoading[sName] = nil
	return false
   end
  else
   error(err)
   tAPIsLoading[sName] = nil
   return false
  end
  local tAPI = {}
  for k, v in pairs(tEnv) do
   if k ~= "_ENV" then
	tAPI[k] = v
   end
  end
  _G[sName] = tAPI
  tAPIsLoading[sName] = nil
  return true
end
loadAPI("test.lua")
end
function love.draw()
foo()
end