Re: [Haskell-cafe] Re: FPS: Finalizers not running (was Memoryusageoutside of the Haskell heap)

On 11/9/05, Ketil Malde wrote:

Sebastian Sylvan wrote:

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On 11/8/05, Jan-Willem Maessen wrote:

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Just wanted to let people know that I've been working on improving Data.HashTable, with the help of Ketil Malde's badly performing code

Always happy to help, of course - bad performance R us:-)

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Request: Data.HashTable.Immutable

I'm not sure you really want that - do you wish to copy a large array each time you do an update?

Well if you want a mutable hashtable you use the mutable one. In many cases you want to have a map from generic keys to values that never (or very seldom) change. A Data.Map is usually used in this case, but if you do a lot of lookups it would be nice to have a hashmap that can still be used in pure code. It's basically analogue to Arrays. Sometimes you use IArray and sometimes MArray. In fact the hashmap could be parameterized on an internal Array representation so you could have DiffArray based Hashmaps which support O(1) updates, but still has an immutable interface. /S -- Sebastian Sylvan +46(0)736-818655 UIN: 44640862