Yes, that makes sense, but I'm ok with passing in an identity. I'd like a function like this:
newChanSafe::Identity -> Chan a type Identity = Double -- or whatever -Alex- _________________________________________________________________ S. Alexander Jacobson mailto:[EMAIL PROTECTED] tel:917-770-6565 http://alexjacobson.com On Fri, 23 Apr 2004, Nick Benton wrote: > Channels have identity, so allocating a new one is a side effecting > operation. Having it outside the IO monad would require (for example): > > (newChan, newChan) = (let x = newChan in (x,x)) > > which is wrong. If you wrap newChan in unsafePerformIO then the compiler > will feel free to apply rewrites like the above, which is unlikely to be > what you wanted. > > Nick > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of S. Alexander Jacobson > Sent: 23 April 2004 19:22 > To: Haskell Mailing List > Subject: [Haskell] Why is newChan in the IO Monad? > > Nothing actually happens when newChan is called > except construction of a new datastructure. It > would be nice to have non IO monad code be able to > create a new Chan that gets passed to IO code that > uses it somewhere else. > > Alternatively, is there a way to create a Chan > outside the IO monad? > > -Alex- > > _________________________________________________________________ > S. Alexander Jacobson mailto:[EMAIL PROTECTED] > tel:917-770-6565 http://alexjacobson.com > _______________________________________________ > Haskell mailing list > [EMAIL PROTECTED] > http://www.haskell.org/mailman/listinfo/haskell > _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
