Justin: Member Since 1923
Tue, 15 May 2001 00:12:19 EDT

>    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 
>are not as easily implemented as they can be in other languages, in 
>I've implemented a simple one myself, using a list of pairs 
>(which means it's slow on lookup) and an optional monad to handle the 
>    I guess what I'm wondering is what has been done in this respect. 
>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:

Maybe this is what you're looking for?