Re: [Haskell-cafe] IO is not a monad

Aaron McDaid wrote:

Could seq be changed so that it will not give an error if it finds undefined? Am I right in thinking that seq is supposed to theoretically do nothing, but simply give a hint to the compiler so to speak? If that is true, it should merely attempt to evaluate it, but ignore it if it cannot evaluate it.

⊥ represents any unsuccessful computation, not just the exception that a Haskell implementation throws when it evaluates "undefined". In particular, a program that does not terminate at all can be described as returning ⊥.