Status of nubOrd (Proposal #2629)

Brandon S. Allbery KF8NH allbery at
Mon Oct 6 00:13:11 EDT 2008

On 2008 Oct 6, at 0:07, David Menendez wrote:
> On Sat, Oct 4, 2008 at 3:26 AM, Bart Massey <bart at> wrote:
>> I need to know what the community wants me to do to close
>> out my proposal to add nubOrd to the standard libraries.
>> After ruling out a lot of marginal choices, I guess I see
>> three leading alternatives, all of which have negatives.
>> I'd love to have some feedback on these so I can start
>> thinking about other things.
> I realize I'm coming into this discussion late, but has anyone
> surveyed existing Haskell code to see how often nub is used? How many

It's not so much that nub is used often. it's that it's often  

> If there are really a lot of cases where people need a collection that
> (1) has no duplicates, and (2) preserves an arbitrary order of
> elements, maybe we'd be better off designing a data structure
> specifically for that.

Feel free to contribute.  Make sure it supports the whole spectrum of  
list operations, including list comprehensions.

brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery at
system administrator [openafs,heimdal,too many hats] allbery at
electrical and computer engineering, carnegie mellon university    KF8NH

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