I should have done even 30 seconds of research before sending that last message. RRB has been available in Clojure since 2014 https://github.com/clojure/core.rrb-vector/blob/master/README.md If you use that data structure instead of the normal vector, then concats will perform better.
On Wed, Jul 18, 2018 at 9:59 AM Robert Levy <r.p.l...@gmail.com> wrote: > Ironically, concat is one of the few operations in Clojure that actually > very likely to cause you performance headaches that actually will matter. > Concatting is extremely slow. I think there's a Bagwell functional data > structure (RRB ?) that addresses the performance issues with concat, but to > my knowledge it has not been added to Clojure. > > On Wed, Jul 18, 2018 at 8:17 AM Christian Seberino <cseber...@gmail.com> > wrote: > >> Actually I was just kicked out of paradise. concat always returns a list >> and does NOT return a vector for this (concat [1 2] [3 4]) sadly. >> >> cs >> >> _______________________________________ >> >> Christian Seberino, Ph.D. >> Phone: (936) 235-1139 >> Email: cseber...@gmail.com >> _______________________________________ >> >> >> >> On Wed, Jul 18, 2018 at 2:16 AM, Didier <didi...@gmail.com> wrote: >> >>> It's never a good idea to use the wrong data structure for the job. >>> >>> And thus Clojure takes the stance that it won't make bad ideas easy for >>> you to use. Yet, it will never prevent you from doing anything. >>> >>> If you want to do something bad, you'll need to get your own hands dirty. >>> >>> That's why slow data structure access functions don't exist as standard. >>> That's why data transforms are lazy by default. And why the non lazy >>> variant (transducers) do loop fusion for you. That's why mutability is ugly >>> and requires you to wrap things in extra verbosity. That's why OOP isn't >>> there, and forces you to use the host interop if you want it. That's why >>> there's only recursive loops. Etc. >>> >>> The Clojure standard lib is opinionated. It's not trying to make >>> everything easy and convenient. It's trying to make things simple to reason >>> about, and promote Rich Hickeys opinion of what is a good idea, and what >>> isn't. >>> >>> But, it can afford to be this way, because it made itself a Lisp, >>> meaning it gave you all the power needed to disagree and make your own >>> core, which follows your own opinions of good and bad.[1] >>> >>> Now, I recommend that everyone should have a core library of their own >>> that they keep around for cases like this, where they disagree. >>> >>> And for beginners, I mean, what are you trying to teach them? What >>> problem requires them to add items to the beginning and end of an ordered >>> collection? >>> >>> Anyways, my advice is to teach them concat. It's even nicer then >>> append/prepend. You just give it the arguments where you want them to go. >>> >>> (concat [1] [2 3]) >>> >>> (concat [1 2] [3]) >>> >>> And it works for any type of ordered collections, even arrays. >>> >>> Also, this blog I think does a great job at teaching all this to a >>> beginner >>> https://medium.com/@greg_63957/conj-cons-concat-oh-my-1398a2981eab >>> >>> >>> >>> [1] Except for reader macros. Rich didn't want you to be able to change >>> the whole program syntax in unconstrained ways. That's probably a good >>> thing to at least keep the foundation universal accross code bases. >>> >>> -- >>> 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 >>> Note that posts from new members are moderated - please be patient with >>> your first post. >>> 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 >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "Clojure" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to clojure+unsubscr...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> 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 >> Note that posts from new members are moderated - please be patient with >> your first post. >> 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 >> --- >> You received this message because you are subscribed to the Google Groups >> "Clojure" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > -- 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 Note that posts from new members are moderated - please be patient with your first post. 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
