Funny that you mention ad-hoc data analysis in the bottom part of your comment, because while i was reading the top part, i was thinking "ha, no _way_ am i goin

Funny that you mention ad-hoc data analysis in the bottom part of your comment, because while i was reading the top part, i was thinking "ha, no _way_ am i going to be writing extensive unit tests while doing exploratory data analysis..." For what it's worth, of course i do rudimentary testing before running things for an hour, but there's often small things that are missed that don't show up on smaller datasets for one reason or another. Of course it couldn't catch every possible runtime error, but in my real-world experience I have definitely come across things that would have shown up during compilation with strong type, _especially_ if the array sizes were encoded into the type system. There's something practical about how Haskell makes you think about program structure and data representations ahead of time instead of it being an afterthought; but I agree, this can also be restrictive when you are being exploratory.