Adding Dependencies

In this chapter, we'll add an argument parser called argparse to our project and verify it loads correctly with lx lua.

Since we're building a CLI, we need something to parse flags and arguments. We'll use version 0.7 of argparse:

lx add argparse@0.7

Lux will download and install argparse and any transitive dependencies. You should see output similar to:

Added argparse 0.7.1
...

note

This may take a while depending on your internet connection!

tip

To avoid hitting rate limits on hosts like GitHub, see How to configure access tokens.

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:

lx lua

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.