Library proposal: add a Location interface for element-wise operations on Data.Map (#4887)

Johan Tibell johan.tibell at
Wed Jan 12 22:53:02 CET 2011

On Sat, Jan 8, 2011 at 10:05 AM, Johan Tibell <johan.tibell at> wrote:
> So the baseline insertWith' is 35% faster than the Location-based
> insertWith' which is 7% faster than composing lookup and insert, on
> the "insertWith' update" benchmark.
> Can we get the Location-based implementation to perform closer to the
> current implementation?

I tried to improve the performance today without much success (but
much staring at Core). I wonder if the extra allocation of Path data
constructors is hurting performance.

Is it worth adding this Interface for all its coolness? Simply using
'lookup' plus 'insert' is simpler, as powerful, and only 7% slower.


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