> > Contrived example follows: > > > module Module1 (mod1) where > > import Module2 > > > > glob1 :: IORef Int > > glob1 <- mod2 >>= newIORef > > > mod1 :: IO Int > > mod1 = readIORef glob1 > > > module Module2 (mod2) where
> > import Module1 > > glob2 :: IORef Int > > glob2 <- mod1 >>= newIORef > > > mod2 :: IO Int > > mod2 = readIORef glob2 > This is illegal because you're only allowed to use ACIO > in top level <- bindings and readIORef isn't (and clearly > could not be) ACIO. (made a couple of changes to quoted example; added import statements and explicit export lists) Even though I never call writeIORef on glob1 or glob2, and can change the example as above so we don't export them, so it's impossible to ever do so? As an alternative, consider module Module1 (mod1) where import Module2 glob1 :: Int glob1 <- return $! mod2 mod1 :: Int mod1 = glob1 module Module2 (mod2) where import Module1 glob2 :: Int glob2 <- return $! mod1 mod2 :: Int mod2 = glob2 Even more artificial, of course. Arguably both of these cases are not ACIO simply because of the non-termination effects, but it's not obvious to me how you tell just by looking at either one's code together with the declared API of the other. Is anything strict automatically forbidden by ACIO? Cheers, Ganesh ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ============================================================================== _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
