jmaessen at alum.mit.edu
Fri Jun 3 10:57:40 EDT 2005
On Jun 3, 2005, at 7:51 AM, Christian Maeder wrote:
> Serge D. Mechveliani wrote:
>> I used to apply FiniteMap.addListToFM.
>> Now, what is its best expression in ghc-6.4 ?
>> Is this
>> \ mp pairs -> Map.union (Map.fromList pairs) mp
>> (the order of the arguments in Map.union is essential).
> This looks fine to me. "best" is hard to meet. I'ld suggest:
> foldr (uncurry Map.insert)
The trouble is, neither of these approaches is demonstrably better for
*all* finitemap implementations. The latter is probably best for
standard binary trees with a balance metric, where union is notoriously
difficult. But for other structures the union approach may work better
(a randomly-balanced tree I'm fiddling with has this property, I
That argues for presence in the library.
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