> spent hours figuring out how to debug-print a value from a pure function What method did you try to figure it out? If I google "haskell debug print pure fun

> spent hours figuring out how to debug-print a value from a pure function What method did you try to figure it out? If I google "haskell debug print pure function", the first three results I get are: * https://hackage.haskell.org/package/base-4.12.0.0/docs/Debug-Trace.html https://hackage.haskell.org/package/base-4.12.0.0/docs/Debug... * https://stackoverflow.com/questions/13265783/trace-output-in-pure-function https://stackoverflow.com/questions/13265783/trace-output-in... * https://en.wikibooks.org/wiki/Haskell/Debugging https://en.wikibooks.org/wiki/Haskell/Debugging and they all have easy, one-line, correct examples of how to do it, within the first 20 seconds of reading. (This is not to criticise -- sometimes one misses the forest for the trees -- as a professional Haskell consultant who runs trainings I am genuinely interested into what problems people face and why.)