Don't get me wrong, Haskell is a great language, but it's not very "mathematical". It just has terrible ambassadors that give the impression that category theory and Haskell are synonymous. They're not, Haskell has its own breed of categeory theory that I prefer to call Haskellory theory.
This is a reasonable introduction to Haskell that does away with that Haskegorical nonsense:
It isn't ambassadors doing that, it is detractors.
>This is a reasonable introduction to Haskell that does away with that Haskegorical nonsense
Note that one of the authors, Don Stewart is almost certainly the biggest haskell ambassador in the history of the language. Which reinforces my other statement quite nicely.
Really? Is that because they don't like Haskell, or because they don't like programming in general?
Functional programming in Haskell makes it fairly easy to write fast code, though Haskell in particular is tricky to reason about space-wise (due to laziness).