Adding Dependencies
Lua has a very little standard library, so let's download some helpful
dependencies before we start writing any code. Since we want to develop a CLI,
we need a library capable of parsing flags and arguments. To do so, we will use
version 0.7 of argparse.
We'll install it with the following command:
lx add argparse@0.7
This may take a while depending on your internet connection!
Testing Our Changes
To check whether argparse is loaded we can enter a Lua REPL and play around
with our code. However, just running lua will not work. To enter a
lua REPL with our dependencies loaded, we need to run the following command instead:
lx lua
This acts as a direct wrapper around the regular lua program.
Once in the REPL, let's try to require our argparse code. Type require("argparse").version
and press enter. Below is the successful output:
Lua 5.4.7 Copyright (C) 1994-2024 Lua.org, PUC-Rio
> require("argparse").version
0.7.1
>
We're now ready to start writing some serious code in the next chapter.
You can exit the REPL by pressing Ctrl+D or typing os.exit() and pressing enter.