At 16:13 10/11/04 -0800, John Meacham wrote:
... (This wouldn't help G. Klyne of course). I've always wondered why a non-monadic version of is not provided in the GHC libs...
Sometimes you are willing to pay an arbitrary setup cost for very fast future lookups. for things like symbols tables for instance. This is where a constant non-monadic hash would be quite useful, especially since you know it is immutable you can choose things like the number of buckets more inteligently.
Indeed. In a past life, I implemented an IP address translation system where a key requirement was that performance would not degrade as the number of active addresses increased. Performance being very dominated by lookups. The solution adapted an hash table scheme with O(1) lookup characteristics. Insertion/deletion costs were sub O(N), but with a very high constant factor. (The main problem was complexity: the lookup table was a pig to debug!) #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact