[Haskell-cafe] Referential Transparency and Monads

Hi, How exactly do monads “solve” the problem of referential transparency? I understand RT to be such that a function can be replaced with a actual value. Since a monad could potentially encapsulate any other value—say, data read from a keyboard—doesn’t that violate the assumption of RT on monads? Or does RT ignore the encapsulated data and just view the “action” performed by the monad as the “value” of the monad? Just curious as to the rationale behind referential transparency and how it applies to monads. Cheers, Mark Spezzano No virus found in this outgoing message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.48/2048 - Release Date: 8/04/2009 7:02 PM