nubBy flips args to nubbing function
The nubBy function in the List library seems to flip
the order of arguments to the nubbing function from
that specified in the prelude:
nubBy eq (x:xs) = x : nubBy eq (filter (\y ->
not (eq x y)) xs)
I.e., it seems to use (eq y x) instead of (eq x y).
This doesn't matter of course for symmetric nubbing
functions, but I just tried to use it with the
following function:
subsetEq :: (Eq a) => [a] -> [a] -> Bool
subsetEq l1 l2 = all (`elem` l2) l1
> nubBy subsetEq [[1],[1,2],[2,3],[2]]
[[1],[1,2],[2,3]]
> nubBy (flip subsetEq) [[1],[1,2],[2,3],[2]]
[[1],[2,3],[2]]
Trac metadata
| Trac field |
Value |
| Version |
5.0 |
| Type |
Bug |
| TypeOfFailure |
OtherFailure |
| Priority |
normal |
| Resolution |
ResolvedRemind |
| Component |
None |
| Test case |
|
| Differential revisions |
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| BlockedBy |
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| Related |
|
| Blocking |
|
| CC |
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| Operating system |
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| Architecture |
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