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by eru 5975 days ago
Exactly. (However Data.Set is only defined for comparable values, i.e. the Ord typeclass, not Eq.)
1 comments
jrockway 5975 days ago
That is an efficiency hack to make it O(n log n) instead of O(n^2) rather than an intrinsic property of sets, functors, or Haskell :)
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eru 5975 days ago
Indeed. But Hindley-Milner [1] type systems have trouble expressing commutative stuff in general.

[1] I hope I got the names correct.

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