Haskell Typeclasses vs Interfaces

What are the main differences between Haskell typeclasses and interfaces in other programming languages?

Haskell typeclasses are a way to define generic interfaces that can be implemented by different types, while interfaces in languages like Java or C# are more rigid and require explicit implementation. Typeclasses allow for ad-hoc polymorphism, meaning you can define functions that work on any type that implements a certain typeclass.

Can you give me an example of how a typeclass works in Haskell?

Sure! Here's a simple example: you can define a typeclass called Show that requires a show function. Any type that implements Show must provide its own version of show. For instance, you could have a data type for a Point and implement show to display its coordinates.

How do typeclasses compare to interfaces in terms of flexibility?

Typeclasses in Haskell are more flexible because they allow for default implementations and can be extended without modifying existing code. In contrast, interfaces in languages like Java are more strict, requiring all implementing classes to provide their own implementations.

Are there any performance implications when using typeclasses?

Yes, there can be performance implications. Typeclasses introduce a level of indirection, which can lead to runtime overhead. However, Haskell's compiler can optimize typeclass usage in many cases, so the performance impact is often minimal.