So...there's just no good way to avoid the duplication?
On Tue, Jan 20, 2009 at 11:10 PM, wren ng thornton
Andrew Wagner wrote:
Strange little bit of code: http://moonpatio.com:8080/fastcgi/hpaste.fcgi/view?id=829#a829
If I do any of the following, all of which seem natural to me, it fails to typecheck:
1. move f out of the 'where' clause (with or without a type signature) 2. put the same type signature on f as is on (/\) 3. replace f with (/\) completely
What's going on here?
:t (nub .) . (++) (nub .) . (++) :: (Eq a) => [a] -> [a] -> [a]
:t foldr (map . (nub .) . (++)) foldr (map . (nub .) . (++)) :: (Eq a) => [[a]] -> [[a]] -> [[a]]
The type you give to (/\) is more restrictive than the type of the expression, and f uses the generality of the expression.
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