On Apr 5, 2006, at 4:51 PM, John Meacham wrote:
On Wed, Apr 05, 2006 at 10:34:09AM -0500, Spencer Janssen wrote:
How about an implementation that sets the deepSeq'd bit *after* each field has been successfully deepSeq'd? deepSeq'ing a cyclic structure would behave just like an infinite structure.
what would be the point of having a bit then?
Because deepSeq's cost to evaluate a list that will eventually be required is linear. The maximum number of deepSeq calls (and recursive calls) you can do over any structure is simply the number of nodes. Consider: foldr (\ a as -> deepSeq (a : as)) [] $ some list With the bit ==> one deepSeq per cons, then we hit the 'is-pre- deepSeqd' bit. Without the bit ==> O(n^2)
in any case, we should talk about the meaning of deepseqing something, not its implementation.
depth limited recursive seq seems like the best route to me.
John
-- John Meacham - ⑆repetae.net⑆john⑈ _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://haskell.org/mailman/listinfo/haskell-prime