On 28 Jan 2010, at 20:07, Steve Schafer wrote:
The data are currently in a large lookup table. To save space, I'd
like
to convert that into a sort of hash function:
hash :: key -> value
My question is this: Is there any kind of generic approach that can
make
use of the knowledge about the internal redundancy of the keys to come
up with an efficient function?
There are minimal perfect hash functions; there are some libraries
mentioned here, though they are not in Haskell code:
http://en.wikipedia.org/wiki/Perfect_hash_function
This is suitable when you do a lot of lookups with few key updates. An
alternative might be Data.Map, where lookups have time complexity
O(log n), n = size of map.
Hans
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