Combining Bag/OrdList?

Ben Gamari ben at
Sat Jun 2 17:39:16 UTC 2018

Andreas Klebinger <klebinger.andreas at> writes:

>  > we are free to improve the implementation of Bag in the future so 
> that it doesn’t preserve order
> Imo we lost that ability by exposing consBag & snocBag which imply that 
> there is a front and a back.
> Which at first glance also seem to be already used in GHC with that 
> behavior in mind.
It looks to me like many of the applications of snocBag should really be
using OrdList.

In my opinion we should keep the two types apart and simply be more
careful about when we use each. There is value in being precise about
whether or not ordering of a structure is relevant, even if we don't
take advantage of this in the structure's representation.


- Ben
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