I'm new here :)
Each time I see something like that, I think it looks great, but I'm having a hard time understanding the meaning of the vocabulary used…
Is there any good (free?) resources out there to learn Monoids, Monads, traits, category theory, in short, anything used in functional languages?
This is something that clearly stops me from using functional languages more.
This[1] is a good paper about monads in functional programming. It reads quite similarly to a monad tutorial, but with a little more formality.
As for actual category theory, I've enjoyed the first few chapters of "Algebra: Chapter 0", by Aluffi.
If you're after more type theory, the usual recommendations are "Types and Programming Languages", by Pierce, and "Software Foundations", also by Pierce.
[1] http://homepages.inf.ed.ac.uk/wadler/papers/marktoberdorf/ba...
http://science.raphael.poss.name/categories-from-scratch.htm...
If you feel it's still too opaque, feel free to let me know anything specific and I will try to amend the articles with further explanation.
Categories/Functors/Monads will appear in the series in the future, as these arise as generalizations of topics discussed so far.
Has articles about Category Theory, Monads, etc... for beginners.