Actually, I just had a thought. What if we ran ST computations with a different state token type? Say, State# FakeWorld? Would that let them escape the hack? David FeuerWell-Typed, LLP -------- Original message --------From: David Feuer <david@well-typed.com> Date: 3/15/17 6:38 AM (GMT-05:00) To: GHC developers <ghc-devs@haskell.org> Subject: Another strictness analysis wrinkle I don't see how we can take advantage of this, but IO and ST seem quite different from a strictness analysis perspective. The whole I/O hack is completely unnecessary for ST. Ugh. David FeuerWell-Typed, LLP