From the bit of Haskell I've managed to learn, it's a great language, and I can see how an awful lot of the errors that you can make in other languages will probably be avoided in Haskell, but I've never understood the (frequently repeated) claim that
"If your program compile it will be very close to what the programmer intended".
There's nothing I've seen in Haskell, or any other language, that will prevent you implementing the wrong algorithm, or the wrong business rules etc. If you're doing a phsyics simulator (to take an example I've played around with), Haskell is not going to stop you badly miscalculating the gravitational effect of multiple objects, or calculating the mass of an object incorrectly.
"If your program compile it will be very close to what the programmer intended".
There's nothing I've seen in Haskell, or any other language, that will prevent you implementing the wrong algorithm, or the wrong business rules etc. If you're doing a phsyics simulator (to take an example I've played around with), Haskell is not going to stop you badly miscalculating the gravitational effect of multiple objects, or calculating the mass of an object incorrectly.