使用该模块

-- The following assumes that trim module is installed or in the caller's package.path,
-- which is a built-in variable that Lua uses to determine where to look for modules.
local trim = require "trim"

local msg = "    Hello, world!      "
local cleaned = trim.trim_all(msg)
local cleaned_right = trim.trim_right(msg)
local cleaned_left = trim.trim_left(msg)

-- It's also easy to alias functions to shorter names.
local trimr = trim.trim_right
local triml = trim.trim_left