[Haskell-beginners] 'Simple' function

[Marcin Mrotek]

> This is a common source of confusion. A value of type IO a for some a is not
> an impure function because it is not a function. Its evaluation is
> completely pure and referentially transparent: every time you evaluate
> `getLine`, you get the same IO String value. The only observable difference
> is under execution, but we don't expect execution to be pure: we only expect
> evaluation to be pure.

Yeah, this is what I was trying to say in the latter part of my post,
but I guess I ended up confusing the matter more :(

Best regards,
Marcin Mrotek