Yes, it does look like an ideal use case. I really really love Haskell, but I wonder if it's a rational decision to use it in comparison to an eager ML (OCaml,

Yes, it does look like an ideal use case. I really really love Haskell, but I wonder if it's a rational decision to use it in comparison to an eager ML (OCaml, F# or SML). Much simpler languages. The amount of language extensions plus laziness make the learning curve of Haskell quite steep! Still, I love this. Keep up the good work. I think that during the 2020s we will see a lot of efforts to move software errors to compile time with fancier type systems (dependent, linear, etc). I'm betting on a slightly different approach than Haskell, which I think is too complex and will never fit all use cases. I think the best approach is to have a great language to quickly build DSLs and formal verification methods (ranging from lightweight like property-based testing or type systems to heavyweight like abstract interpretation or theorem proving). So, essentially Racket (Lisp) + lots of formal techniques in a nice package.