2) you can't use >>= in an if condition
look at the first if in base package that i is not a comment ok <- getProcessTimes ... if toBool ok then do since getProcess has many actument's this is good code, but imagine it was a short IO function if toBool { getProcessTimes ... } then do looks much better you can't pipe the result of getProcessTimes into the if conditional. Unless you use a lambda of course.
3) or imagine you want to fill it in some 3-tuple or a record type.
What does this mean?
someIOFunction ({getProcessTimes ...}, foo, bar) someIOFunction (foo { bar = {getProcessTimes ...}})
4) res <- fmap pureFunction ioFunction === let res = pureFunction { ioFunction}
From a distance, let and monadic bind are just different forms of name binding.
But haskell's let has an effectlessness that makes it declaratively different from its cousin in, say, ocaml.
This is no small change you're proposing.
You might have misunderstood. The 'let' in the do notation is already different from the normal 'let' in that it doesn't have an 'in' for example. {} should of course only work inside a do block. silvio