[andolanra]

"[Haskell is], indeed, heavily founded on mathematical theories (category theory and lambda calculus)."

This is a pretty common reason given for why Haskell is "math-ey", but I'd argue it's simultaneously a bit misleading and also a bit boring. The part that's misleading is "Haskell is based on category theory": while a major feature of programming in Haskell (the monad abstraction) was inspired by category theory, the truth is that moment-to-moment programming in Haskell doesn't have much to do with category theory unless you want it to. Even monads require zero knowledge of category theory in order to understand or use! Some people find usefulness in category-theoretic abstractions, but many others—myself included!—don't at all: I've actually improved the performance of Haskell code in the past by cutting out category-theoretic abstractions in favor of simpler code, and by now I steer clear of most Haskell code that wears category theory on its sleeve.

The part that's boring is that "Haskell is based on lambda calculus". The lambda calculus is a mathematical description of a simplified model of computation with functions and binding… and that's basically it. Almost every modern programming language uses variable binding as a basic feature, and in that sense, is "based on lambda calculus". Plenty of other languages, for example, are inspired deeply by Lisps (like JavaScript or Ruby) which in turn were directly inspired by the lambda calculus, but I don't think that lineage makes them particularly math-like. Instead, being "based on lambda calculus" usually just means that they have variables and closures—something true of almost every popular language used today!

Now, Haskell-as-practiced can have a fair bit of math-inspired abstraction in it, which can be daunting to someone new to Haskell. Some of that abstraction is useful (e.g. monads), some of it isn't, but the fact that it exists is more about vocal Haskell programmers and bloggers, and much less about Haskell-the-language being "heavily founded on mathematical theories". And you'll also find plenty of programmers and bloggers arguing against the more math-heavy parts of the ecosystem: just in the past month I've seen plenty of Haskell programmers passing around links like https://www.simplehaskell.org/ which advocates for exactly this less-mathy approach to Haskell.

[the_duke]

The big problem here is documentation.

Most beginner Haskell resources go into complicated monad explanations very early on, instead of just showing how to use them like a tool. Intermediate resources are even worse.

[bawolff]

I disagree about all computer languages being about lambda calculus. Lambda calculus is fundamentally about functions being first class objects (as opposed to say sets, if we are taking a math prespective). Well that has become a more popular language feature, plenty of languages do not support this. C being an obvious answer.

I'm not a haskell programmer, but I agree with you on the math aspect being largely over excited bloggers. Sometimes i feel like half the haskell articles posted here are taking some simple concept, wrapping it up in heavy duty mathematical machinery, not using the machinery for anything, and then proclaiming profound insight. The other week there was a haskell article on hn literally talking about how great it is that strings form a semigroup under concatenation, because i guess nobody realized you could concat strings before that.