PROPOSAL: Add `disjoint` method to `Data.IntSet`

Joachim Breitner mail at
Tue Dec 19 15:01:54 UTC 2017


Am Dienstag, den 19.12.2017, 13:44 +0100 schrieb Andreas Abel:
> +1 for "disjoint".


> I think "overlaps" falls below the Fairbairn threshold. 


>  I always 
> wondered why there is a "notMember" function in the Set interface, 
> saving us 3 key presses.

Probably because of use like this:

   filter (`notMember` seen) todo            -- pretty


   filter (not . (`member` seen)) todo       -- too many parenthesis.

Of course 

   filter (\x -> not (x `member` seen)) todo -- is also ok

And I will refrain from pointing out that with the idea of no-white-
space-means-higher-precedence[1] would allow

   filter (not . `member`seen) todo          -- too many parenthesis.


>  One thing to consider: Data.Set should then also be equipped with a 
> function "disjoint", to keep interfaces in sync.


Joachim Breitner
  mail at
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