Typeclasses

Typeclasses provide a way to define operations that can be performed on different types without requiring them to share a common superclass. This is a powerful feature in some programming languages, particularly functional languages like Haskell. Instead of inheriting methods from a parent class, types *opt in* to a typeclass by providing an implementation for the typeclass's defined functions. This allows for ad-hoc polymorphism, meaning a function can operate on values of any type that has implemented the relevant typeclass.

The core idea is that a typeclass defines a set of functions, and any type can be made an "instance" of that typeclass by providing concrete implementations for those functions. For example, a typeclass might define a `show` function that converts a value to a string. Integers, booleans, and custom data types could all be made instances of this `show` typeclass by providing their own unique `show` implementation.

This approach contrasts with traditional object-oriented inheritance, where methods are inherited from a superclass. Typeclasses allow for a more flexible and extensible form of polymorphism. It enables code reuse and makes it easier to add new behaviors to existing types without modifying their original definitions. The compiler can then ensure that a function is only called with arguments whose types are instances of the required typeclass, leading to strong compile-time guarantees.

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