A lovely post. The Haskell-I/O-inspired brainflip is very nicely described. I've never been a Haskell programmer, but a thing that struck me about the Idris bo

A lovely post. The Haskell-I/O-inspired brainflip is very nicely described. I've never been a Haskell programmer, but a thing that struck me about the Idris book (which is mentioned in one of the comments on that post) is its very calm introduction to monadic I/O in terms of the separation between evaluation and execution - which the author of the book (and developer of Idris) manages without using the word monad, I assume deliberately. There are a lot of appealingly surprising things in Idris. Other languages that have given me that "oh...!" feeling in the further past include Prolog and term-rewriting languages like Pure (and to an extent TeX).