GHC *is* resource hungry

[Ralf Hinze]

> 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.)

Your bet is most likely the correct one (yes, I peeked at Chris' HW2002 paper).

> GHC doesn't try to hash-cons types, because it usually doesn't matter,
> but I bet it does here.

Would this be a major rewrite? [As an aside, a similiar problem showed up
when generating conversion functions for generic representation types.]

Cheers, Ralf

> | -----Original Message-----
> | From: glasgow-haskell-bugs-admin at haskell.org
>
> [mailto:glasgow-haskell-bugs-admin at haskell.org] On
>
> | Behalf Of Ralf Hinze
> | Sent: 28 May 2003 15:32
> | To: glasgow-haskell-bugs at haskell.org
> | 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
> |
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