Not it doesn't. getChar has the type signature IO Char. The IO type is abstract. GHC happens to implement it by a state monad. But in, e.g., hbc it is implemented in a totally different way, more like a continuation monad.
Peeking inside an implementation of IO can be illuminating, but one must remember that IO is abstract. -- Lennart On Mon, Feb 9, 2009 at 10:26 AM, Tony Morris <tmor...@tmorris.net> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Gregg Reynolds wrote: >> The point being that the metalanguage commonly used to describe IO >> in Haskell contains a logical contradiction. A thing cannot be both >> a value and a function, but e,g, getChar behaves like a function and >> has the type signature of a value. > getChar has the signature RealWorld -> (RealWorld, Char) > > - -- > Tony Morris > http://tmorris.net/ > > ********************************************************* > * Anteromedial Heterotopic Osseous Impingement Syndrome * > ********************************************************* > > http://www.ajronline.org/cgi/content/full/178/3/601 > "can result in chronic ankle pain, especially in athletes and the > younger population (15-40 years old)" > > http://radiographics.rsnajnls.org/cgi/content/figsonly/22/6/1457 > "Soft-tissue and osseous impingement syndromes of the ankle can be an > important cause of chronic pain, particularly in the professional > athlete." > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQFJj/bcmnpgrYe6r60RAicqAJ9z3f+aM/k+gDv8d5yAaNSCFf9NVQCfX3Qo > ItFqQSWPDUE2h9WS+axAXV8= > =c8Nw > -----END PGP SIGNATURE----- > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
