Re: [Haskell-cafe] Usage of . and $

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sum . IntMap.elems . IntMap.IntersectionWith (\x y -> x*y) queryVector rationalProjection

Composition with (.) builds a function, but you eventually want an Int, so we can't just use (.), but we can come pretty close. (sum . IntMap.elems . IntMap.IntersectionWith (\x y -> x*y) queryVector) rationalProjection