Expressing do block using only monadic bind syntax

Question

As far as I know, do blocks in Haskell are just some kind of syntactic sugar for monadic bind operators. For example, one could convert

Answer 1

Yes, all of them can be converted to bind syntax; in fact, they are converted internally by the compiler.

I hope this translation of your example gives you the hint:

main = readFile "foo.txt" >>= \f ->
       (print $ "prefix " ++ f) >>
       (print $ f ++ " postfix")