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bicycle1885/gist:c4553dda851e4999d4c4

Created July 18, 2014 03:39
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deduction error
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gistfile1.txt
{-# LANGUAGE FlexibleContexts #-}
import qualified Data.Vector.Generic as G
fooG :: (G.Vector v Int) => Int -> v Int -> v Bool
fooG x = G.map (> x)
-- hello.hs:5:10:Could not deduce (G.Vector v Bool) arising from a use of ‘G.map’
-- from the context (G.Vector v Int)
-- bound by the type signature for
-- fooG :: G.Vector v Int => Int -> v Int -> v Bool
-- at hello.hs:4:9-50
-- In the expression: G.map (> x)
-- In an equation for ‘fooG’: fooG x = G.map (> x)
@ruicc
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ruicc commented Jul 18, 2014 

{-# LANGUAGE FlexibleContexts #-}
import qualified Data.Vector.Generic as G

fooG :: (G.Vector v Bool, G.Vector v Int) => Int -> v Int -> v Bool
fooG x = G.map (> x)

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