Making Our Own Types and Type Classes

[[deleted user]]

I think that this chapter tried to cover too much. Types and type classes (a kind of overloading that enables polymorphism), along with support for record syntax, help make Haskell more powerful, but without some hands-on practice, the syntax differences quickly blurred together. On the other hand, the discussion about data structures, especially the tree, helped pull a lot of Haskell material together.

Functors were a new concept for me, and I am still unsure about where they are best applied.

For those of you, like me, who are starting to be frustrated by the stream of concepts, without being able to see the bigger picture of how they come together in an application, you might jump to Chapter 10 for these kinds of examples.

[Aleksander]

I can’t agree more, this is exactly how I feel about Haskell and this book in general. I came back to reading it after couple of weeks, and now I can’t figure out what’s going on - syntax for different things looks the same, and looking for those things in long chapters doesn’t make it easier :) I guess I’m more frustrated with myself not remembering stuff and not spending sufficient time learning this language than with this book, which I think is still good.

Nice thing about functors in object-oriented languages is that they can be overloaded, hold a state, and share static members between different instances, basically all nice things that come with classes.