Chapter 8.2: Customizing Output

Your banking system works, but let’s be real... it’s a bit plain.

If you want to make your program more user-friendly (and easier to read), adding some color and style to your terminal output can make a huge difference.

Step 1: Meet Kennels

GLang doesn’t include built-in styling tools by default. That’s where kennels come in, pre-made code packages you can download and use in your projects.

You can learn more about kennels here.

For this chapter, we’ll use a kennel called fancy-terminal, it gives you easy-to-use color and text style controls through string expressions!

Step 2: Installing and Using fancy-terminal

First, make sure you’ve installed the kennel:

glang install https://github.com/george-language/fancy-terminal/releases/latest/download/fancy_terminal.kennel

Then import it into your program:

fetch "fancy_terminal@latest"; # enables color and style support

bark(GREEN + "All systems ok." + RESET);
bark(RED + "A critical error occurred!" + RESET);

How it works: Each color (like RED or GREEN) is just a special string variable that tells your terminal to display text in that color until it hits a RESET. You can also mix and match styles like BOLD, ITALIC, or UNDERLINE to make your output more styled.

For a full list of supported colors and styles, check out the official docs.

Step 3: Applying Styles to Your Banking System

Now that you’ve got fancy-terminal installed, you can make your bank’s messages easier to read (and way cooler). To import fancy-terminal, we use the fetch syntax:

fetch "fancy_terminal@latest";

More info on importing kennels here

For example, in system.glang, you can highlight error messages in red:

fetch std_hashmap;
fetch std_format;
fetch "fancy_terminal@latest";
fetch "account.glang"; # we need the 'account_exists' function

func make_deposit(accounts, name, amount) {
    if account_exists(accounts, name) {
        # account exists, so make the deposit by setting 'name: amount'
        hashmap_set(accounts, name, amount);
    } otherwise {
        bark(format(RED + "Error: account '{}' not found" + RESET, name));
    }
}

func make_withdrawl(accounts, name, amount) {
    if account_exists(accounts, name) {
        obj og_amount = hashmap_get(accounts, name);
        obj new_amount = og_amount - amount;

        # can't withdraw an amount past 0
        if new_amount < 0 {
            bark(RED + "Error: invalid balance after withdrawl" + RESET);

            give null; # return and stop the function
        }

        hashmap_set(accounts, name, new_amount);
    } otherwise {
        bark(format(RED + "Error: account '{}' not found" + RESET, name));
    }
}

You can even go wild with color-coded output:

• Green for success ✅
• Red for errors ❌
• Yellow for warnings ⚠️
• Blue for informational messages ℹ️

What's Next

Keep coding! Developers are always needed everywhere, no matter what. You can write other programs in GLang, or move on to bigger languages like Python or JavaScript. When it comes to software, the world is your oyster.

Congrats 🎉🎉