Elm vs PureScript: What are the differences?

Introduction:

When comparing Elm and PureScript, two functional programming languages that compile to JavaScript, there are certain key differences that developers should be aware of before choosing one over the other.

1. Type System: Elm comes with a simpler and more restrictive type system compared to PureScript. Elm's type system is designed to be beginner-friendly, providing strong guarantees against runtime errors. On the other hand, PureScript offers a more expressive type system with features like higher-kinded polymorphism and type classes, making it more powerful but also potentially more complex for newcomers.

2. Interoperability: PureScript provides better interoperability with existing JavaScript code due to its ability to seamlessly call JavaScript functions and use JavaScript libraries. Elm, on the other hand, has a more restricted approach to JavaScript interop, limiting direct interaction with JavaScript in favor of a more controlled environment.

3. Bundle Size: Elm focuses on simplicity and ease of use, which results in smaller bundle sizes compared to PureScript. Elm's compiler aggressively optimizes output code, resulting in efficient and compact JavaScript files. PureScript, while providing more language features and flexibility, can lead to larger bundle sizes if not carefully managed.

4. Learning Curve: Elm is known for its gentle learning curve, with a strong focus on simplicity and guided learning materials. PureScript, with its more advanced type system and features, can have a steeper learning curve, especially for developers new to functional programming concepts.

5. Ecosystem and Tooling: PureScript has a more mature ecosystem and a larger number of libraries available, thanks to its longer presence in the functional programming community. Elm, being more opinionated and tightly controlled, has a smaller ecosystem but a consistent and vetted set of tools and packages.

6. Community Support: Elm has a strong and active community known for its helpfulness and focus on beginner-friendly resources. PureScript, while also having a supportive community, may require more self-reliance and deeper understanding of functional programming principles to fully leverage the available resources.

In Summary, Elm emphasizes simplicity and safety, while PureScript offers more expressiveness and flexibility, catering to different preferences and requirements in functional programming projects.