At 2002-08-18 20:19, Jay Cox wrote:

#ST> runST (newSTRef (3::Prelude.Int)) # #Ambiguous type variable(s) `a' in the constraint `PrelShow.Show a' #arising from use of `PrelIO.print' at <No locn> #In a 'do' expression pattern binding: PrelIO.print it

I don't understand this either, actually: $ ghci -fglasgow-exts -package lang ___ ___ _ / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 5.04, for Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package base ... linking ... done. Loading package haskell98 ... linking ... done. Loading package lang ... linking ... done. Prelude> :module ST Prelude ST> :type runST Inferred type is less polymorphic than expected Quantified type variable `s' escapes Expected type: ST s a -> t Inferred type: (forall s1. ST s1 a) -> a Prelude ST> What's up with that? Can't I even look at the type? Is this the monomorphism restriction or something? -- Ashley Yakeley, Seattle WA