Simplify Your Code: Functional Core Explained

Host

Welcome to today's episode! We're diving into a topic that often leaves developers scratching their heads: simplifying your code. Why is it so important? Well, tangled code can lead to long hours of debugging and frustration. Today, we have expert Arham Jain with us to break down the concept of 'Functional Core, Imperative Shell.' Arham, thanks for joining us!

Expert

Thanks for having me! I'm excited to discuss this topic. Essentially, the idea is to separate your core business logic from the side effects in your code.

Host

That sounds interesting! Can you explain what you mean by 'functional core' and 'imperative shell'?

Expert

Absolutely! The functional core of your application consists of pure functions, which means they don't have side effects. They only rely on their input to produce output. In contrast, the imperative shell deals with side effects—things like database interactions and network requests.

Host

Got it! So, why is this separation beneficial?

Expert

When you separate these two components, it makes your code much easier to test and maintain. You can test your functional core in isolation without worrying about external factors. Plus, if you need to change something in the imperative shell, you can do that without affecting your core logic.

Host

That sounds like a dream for a developer! Can you give us an example of what this looks like in code?

Expert

Certainly! Let's say you have a function that sends expiration emails to users. If you mix your business logic with side effects, it can get messy. For example, your function might directly call the email service and access the database all at once.

Host

That sounds complicated!

Expert

Exactly! Instead, we can create a functional core that filters expired users and generates the emails separately. The imperative shell would handle sending those emails using the results from the functional core.

Host

So how would that look in practice?

Expert

Here’s a simplified version. In the functional core, you would have a function that gets expired users based on a cutoff date, and another function that generates the email content. Then, in the imperative shell, you'd just call those functions to get your work done.

Host

That really simplifies things! Can you share a quick example of how easy it would be to add new features?

Expert

Sure! Let’s say you want to send reminder emails as well. You just create a new function in the functional core that generates those reminder emails, and then call it from the imperative shell. It's that simple!

Host

Wow, I see how that can save time and reduce bugs. Any final thoughts for our listeners?

Expert

Just remember, keeping your business logic separate from side effects makes your code cleaner, easier to test, and more adaptable to changes. It's a game changer!

Host

Thank you, Arham! This has been incredibly insightful. If you're a developer, consider applying the functional core and imperative shell pattern to simplify your code.

Expert

Thanks for having me!