What is the reason that Haskell does not have methods?

Haskell is a purely functional programming language, which means that it does not have the concept of "methods" in the same way that object-oriented programming languages like Java or Python do.

In Haskell, functions are the basic building blocks of programs, and they operate on data by taking one or more arguments and returning a result. Functions in Haskell are defined outside of any particular class or object, and can be used independently in any part of the program.

Instead of methods, Haskell has a concept called "type classes" which provide a way to define functions that work on different types of data. Type classes are similar to interfaces in object-oriented programming, but they are more powerful because they can define not only the functions that should be implemented for a type, but also the behavior of those functions.

For example, the Eq type class in Haskell defines the functions == and /= that can be used to test for equality and inequality between two values of any type that is an instance of the Eq type class. This allows you to write generic functions that can work on many different types of data, without having to explicitly define separate functions for each type.