On Thursday, 2003-08-14, 07:20, CEST, Tn X-10n wrote:
hai guys
is it possible to convert IO Bool to Bool?
No. The reason for introducing the IO type is to preserve the purity of Haskell, i.e., to ensure that expression evaluation doesn't depend on the state of the outside world and doesn't alter this state.*) Allowing a conversion from IO t to t would nullify this. As you might have noticed, there was (or still is) a discussion about "yet another monad tutorial" on The Haskell Cafe. Some of the messenges and, above all, the monad tutorial itself may help you understand how I/O in Haskell works. There is not a quick answer to your question like: "This way you convert an IO Bool to a Bool." You will have to do some reading to understand the basic ideas of I/O in Haskell. They are quiet different from what you might know from other programming languages. Wolfgang *) This is at least how I would formulate it, others would probably phrase it a bit different. ;-) P.S.: Would you mind to configure your mail client such that your mails also contain a plain text variant of your message?