slightly ot: data structure question

Not really Haskell-specific, but... I need a data structure which is a map from Ints to Doubles; the distribution of the Ints is in the range say 0-20000 and a map will contain somewhere around 100-200 elements. I need to be able to query *very* quickly, insert *quite* quickly, and iterate through the elements very quickly. I'm thinking hash tables, but I'm not sure. Does anyone have any thoughts on this? - Hal -- Hal Daume III "Computer science is no more about computers | hdaume@isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume