Is there an efficient way to make simple databases in Haskell? I
something like a dictionary, hash table or associative container of some kind.
I'm aware that Haskell being pure functional means that those
mean things
are not as easily implemented as they can be in other languages, in fact, I've implemented a simple one myself, using a list of pairs (key,value) (which means it's slow on lookup) and an optional monad to handle the updates/lookups.
I guess what I'm wondering is what has been done in this respect. There is no such thing in the standard library, as far as I can see, and my search through the web has turned up nothing.
Chris Okasaki has developed a whole mess of purely function data structures. He has a book: http://www.cs.columbia.edu/~cdo/papers.html#cup98 Maybe this is what you're looking for? HTH -Justin