Is learning haskell a bad thing for a beginner mathematician?

Question

Haskell is a programming language which uses some concepts from category theory like functor, monad, etc. My question is: Learning intuitive concepts about category from Haskell will ruin my intuition when I learn category theory as a mathematician or it could help developing it?

Answer 1

Just to echo what Mariano said: you may also be interested in reading the various responses to

• Programming Languages Based on Category Theory over at MO.
• Resources to learning Practical Category Theory, ibid
• What programming languages do Mathematicans use, ibid
• and Sigfpe's 11 reasons to learn Haskell as a mathematician.

Answer 2

One problem is that "class Functor", "class Monad" are special cases of categorical concepts, namely the strong ones. With Haskell, you are working in the specific category. That may hinder learning category theory in full generality. Of course, this is just my POV, someone can perceive that obstacle as a no-brainer.

A concrete example. Try to define "instance Monad", i.e. a monad, on the category of rings which sends a ring R to the ring of polynomials with coefficients in R.