ok, I'll check that stuff out. Thanks. It occurs to me this is being compared to something in ruby called partition. I like that name. "partition-by" ... but maybe it was opted to use the simpler name, which I can appreciate.
On that subject, I know "filter" is standard from other languages like Haskell, but I had to learn that it meant "retain-if". To me, "filter" sounds synonymous with "remove". Other candidates: "keep", "preserve". Also, that "-by" convention sounds right for partition or separate, but in the case of filter and remove, "if" sounds better. I suggest breaking from the "filter" tradition and going with "retain-if" and "remove-if". On Sun, Jan 25, 2009 at 6:10 PM, Stephen C. Gilardi <squee...@mac.com>wrote: > > On Jan 25, 2009, at 5:24 PM, e wrote: > > Do folks in the contrib group like this new implementation? >> > > To make contributions to clojure-contrib, you'll need to have a Contributor > Agreement on file with Rich. Please see http://clojure.org/contributing . > > I think your implementation is an improvement over the current > clojure.contrib.seq-utils/separate. > > I have some suggestions: > > - there's precedent for functions that do one thing or another based > on a predicate to be named with a "-by" suffix. > - using vectors for the intermediate results will allow the > separated outputs to preserve the order of the input which might be helpful > to some callers. Since it will still give good performance, I'd opt for that > and promise it in the doc string. > - you might also consider using the names first and rest for the > destructured names you called f and r. I would imagine that's a bit > controversial (because the local names would shadow useful functions), but > arguably it would make the implementation easier to read. > - returning a vector of vectors seems good to me. > > Here's an implementation: > > user> (defn separate-by [pred coll] > (loop [in [] out [] [f & r] coll] > (if f > (if (pred f) > (recur (conj in f) out r) > (recur in (conj out f) r)) > [in out]))) > > #'user/separate-by > user> (separate-by odd? [1 2 3 4 5 6 7]) > [[1 3 5 7] [2 4 6]] > user> > > Whatever you propose will need a doc string. > > After Rich receives your Contributor Agreement and your name is up on the > clojure.org/contributing page, please enter an issue against > clojure-contrib noting that your alternate implementation for the current > clojure.contrib.seq-utils/separate has higher performance while still being > maintainable and correct. Include a complete copy of the code you propose, > preferably as a patch. > > Once the issue is up, I'd follow up in this thread with the issue number > requesting that Stuart consider resolving the issue by adopting your > contribution. > > --Steve > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
