See my next letter -- about compiling of minimum [1 .. (10^6)] with -O. Because, I think, [1 .. (10^6)] is a program which interferes with `minimum', and it depends much on how cleverly this whole expression is complied, for example, `minimum' is in-lined or not. Probably, `minimum' can be rewritten so, that the whole thing will reliably perform in a constant space in the interpreter mode too. And maybe it is, generally, hard to optimize reliably foldl. ----------------- Serge Mechveliani mechel@botik.ru On Fri, Sep 10, 2004 at 12:29:01PM +0200, Jerzy Karczmarczuk wrote:
Serge D. Mechveliani wrote:
The library functions like minimum, maximum, should perform in a constant space: probably, it is easy to write them his way. And ghc-6.2.2-pre shows
Prelude> minimum [1 .. (10^4)] 1
Prelude> minimum [1 .. (10^6)]
*** Exception: stack overflow Prelude>
What do you think of this, please?
Strange, I thought that foldl or foldl1 don't produce such garbage here. I tested with Hugs, you are right also here, this is not specific to GHC.
minim (x:l) = mi x l where mi x (y:q) |x
This one works. But it is brutal, not so exquisite...
Jerzy Karczmarczuk _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users