How to implement Data.Map.insertList*?

[Mirko Rahn]

> Would it not be more efficient to put the list into a new map, and then 
> merge the old and new maps

Sometimes yes. The function

>> insertList_union :: Ord k => [(k,a)] -> Map.Map k a -> Map.Map k a
>> insertList_union kas = Map.union (Map.fromList kas)

is faster on inserting m>n new elements into a map of size n and slower 
on inserting m<n elements.

(http://www.haskell.org//pipermail/libraries/2005-February/003336.html)

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-- Mirko Rahn -- Tel +49-721 608 7504 --
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