For me, there's a pretty big gap between the available educational materials and research papers. My understanding of the academic stuff is mostly intuitive. It isn't until I read a paper like Monadic Parser Combinators [1] or sigfpe's blog [2] that it really becomes concrete.

I find that for a lot of higher-level ideas much of the heavy lifting isn't necessarily through application of functional ideas per se, but through more sophisticated type gymnastics.

Because expressions are often written in short-hand (to expose structure), as well abbreviated and underspecified (to get the compiler to do the work), making sense of academic code can be a challenge.

In another life I'd have dedicated more time to learning the fundamentals (of Programming Language Theory and Category Theory), because I find the whole field insanely facinating. Maybe I'm looking for a short-cut but there isn't one?

[1] http://eprints.nottingham.ac.uk/237/1/monparsing.pdf [2] http://blog.sigfpe.com/