Oh you're right! I was curious and just ran the standard bad `foldl` example and I got a stack overflow in GHCi (8.8.4) but compiling without optimizations in

Oh you're right! I was curious and just ran the standard bad `foldl` example and I got a stack overflow in GHCi (8.8.4) but compiling without optimizations in GHC (to avoid strictness analysis) just led to the program taking over all of my system memory. I do use `runhaskell` quite a bit for my personal utility programs, so I wonder if that's what gave me the impression of those stack overflows (`runhaskell` naturally also gave me a stack overflow). Of course the wider point is that tail calls in Haskell can often end up not taking constant space and in fact moving the function out of the tail position can go back to constant space, but thanks nonetheless for the correction!