Why is there a space leak here?

[Alastair David Reid]

Mark Tullsen <tullsen@cs.yale.edu> writes:

> You have to realize that Alastair Reid is one of the truly great
> Haskell programmers on planet earth.  I'm serious.  So, when he says
> "incredibly subtle space leak" I wouldn't expect the solution to be
> simple.  As far as I can tell, your argument would also apply to
> foo2, which doesn't have a space leak.

Yeah, well, in this case this allegedly "truly great Haskell
programmer" happened to be looking at the problem the wrong way.  I
started out assuming it was a compiler or garbage collector bug and
didn't even think of trying to actually reason about the program using
the CBN calculus.

Blush!

--
Alastair Reid

ps Tell you what, I'll make up for it by making most of the fptools/hslib
   libraries work in Hugs.  If you have read-write access to the cvs 
   repository, all you have to do (as of 20 minutes ago) is:
  
     cvs -d <something> checkout hugs98
     cvs -d <something> checkout fptools/hslibs
     cd hugs98/src/unix
     ./convert_hslibs ../../..   # path points to base of fptools tree
     ./configure --prefix=$HOME
     cd ..
     make install
  
   where <something> is whatever you normally use to get the CVS 
   repository.  Something like this

     :ext:<your username>@cvs.haskell.org:/home/cvs/root

   If you only have read access, you'll need to wait until it gets updated
   (sometime tonight) and then use

     :pserver:anoncvs@cvs.haskell.org:/cvs

   with the password "cvs".