[Haskell-cafe] ANN: HLint 1.2

Neil Mitchell ndmitchell at gmail.com
Mon Jan 12 03:41:03 EST 2009


Hi

> Does GHC specialize map?  If it doesn't, then hand crafted version
> could be faster.

GHC doesn't specialize map, and a hand-crafted one could be faster -
but you then wouldn't get foldr/build fusion. In general HLint tries
to make the code prettier, but sometimes you will need to deviate from
its suggestions when you've profiled etc. To stop HLint warning you
just create Hints.hs and include the line "ignore =
LennartsSuperFastModule.mySpecialisedMap" - full details in the
manual.

>> I found so many 'map' re-implementations in Haskell libraries, even in
>> those, where I thought their programmers must be more experienced than me.
>> Hm, maybe even in libraries by Neil?

I can't really be blamed for making mistakes before HLint ;-)

Thanks

Neil


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