As far as I know, Hugs doesn't hash-cons types, yet it manages to typecheck these pathalogical examples in reasonable time/space. I vaguely recall there being a specific modification to Hugs's typechecker to handle this, but I can't remember what it was.
Cheers, Simon > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Simon Peyton-Jones > Sent: 28 May 2003 15:57 > To: Ralf Hinze > Cc: GHC bugs > Subject: RE: GHC *is* resource hungry > > I bet it's massive types. Translate the program into system > F and see. > (I remember this came up when looking at Okasaki's sequences of code > combinators.) > > GHC doesn't try to hash-cons types, because it usually doesn't matter, > but I bet it does here. > > S > > | -----Original Message----- > | From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > | Behalf Of Ralf Hinze > | Sent: 28 May 2003 15:32 > | To: [EMAIL PROTECTED] > | Subject: GHC *is* resource hungry > | > | Here is a harmless little program (no recursion, no data types) > | which GHC doesn't manage to compile (well, the kernel kills GHC > | after a while on a machine with generous 512MB of main memory > | and 1GB of swap space). > | > | > begin next = next id > | > leaf k i next = next (k i) > | > fork k next = next (\ t u -> k (t + u)) > | > end x = x > | > main = print (begin fork fork fork fork fork fork fork fork fork > fork leaf 0 leaf 0 leaf 0 leaf 0 leaf 0 > | leaf 0 leaf 0 leaf 0 leaf 0 leaf 0 leaf 0 end) > | > | Both Hugs and nhc98 accept it almost immediately. > | > | Cheers, Ralf > | > | _______________________________________________ > | Glasgow-haskell-bugs mailing list > | [EMAIL PROTECTED] > | http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs > > > _______________________________________________ > Glasgow-haskell-bugs mailing list > [EMAIL PROTECTED] > http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs > > _______________________________________________ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs