Proposed addition to Data.FiniteMap

Ketil Malde ketil+haskell at
Tue Nov 9 08:04:07 EST 2004

Graham Klyne <gk at> writes:

> I'd like to propose an addition to the FiniteMap module in the form of
> a monadic version of plusFM_C.  The proposed implementation is pretty
> much a copy of the existing implementation within a do block.

While we're at it, would it be possible (and advantageous?) to add
(Hal Daume III's?) strict versions of addToFM* and friends?  In
general I think there is little to be saved by delaying the evaluation
of the finite map, and it seems laziness sometimes incurs an overhead.

Also (I think I've brought this up before), finite maps seem to be
less than optimal for sequences as keys (e.g. strings), has anybody
experiemented with a trie or a trie/balanced tree combination?  Any
libraries available?

If I haven't seen further, it is by standing in the footprints of giants

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