You say you're not a Haskeller, so I'm going to take what you say about the compiler internals with a grain of salt. > And before you say "why not just break t

You say you're not a Haskeller, so I'm going to take what you say about the compiler internals with a grain of salt. > And before you say "why not just break the runtime model", by e.g. having special debug functions that can do IO while presenting to the runtime as pure functions—well, it's not impossible, in theory, but it's a Hard Problem. import Debug.Trace square x = trace "I'm a Hard Problem" (x * x) main = print (square 3)