And here are some numbers from my machine: (def my-list (list 'a 'b 'c 'd 'e 'f 'g 'h 'i 'j)) (def my-vector ['a 'b 'c 'd 'e 'f 'g 'h 'i 'j])
; ~44ms (time (dotimes [x 1000000] (conj my-list 'k))) ; ~26ms (time (dotimes [x 1000000] (pop my-list))) ; ~100ms (time (dotimes [x 1000000] (conj my-vector 'k))) ; ~100ms (time (dotimes [x 1000000] (pop my-vector))) Clojure makes it very easy to see what's going on, the REPL is your friend ;) On Fri, May 15, 2009 at 4:07 PM, tmountain <tinymount...@gmail.com> wrote: > > I'm no expert, but I think this explain some: > > Clojure's conj function is like Lisp's cons, but "does the right > thing", depending on the data type. It is fast to add something to > the front of the list, and slower to add something to the end. > Vectors are the opposite, you can add to the end fast, slower to add > to the front. This isn't specific to Clojure, it's just the way those > data structures work in any language. So conj adds the item to the > front if it is conjing on a list, to the end if is conjing on a > vector. This is part of how clojure provides a unified method of > handling different type of data structures, which are collectively > called sequences in Clojure. > > Excerpted from here: > > > http://groups.google.com/group/novalanguages/browse_thread/thread/bcb78a59382227e0 > > It's also worth noting that lists are the canonical datatype in Lisp, > so they're probably kept around for that reason as well. > > Travis > > Clojure's conj function is like Lisp's cons, but "does the right > thing", depending on > the data type. It is fast to add something to the front of the list, > and slower to add something to the end. Vectors are the opposite, you > can add to the end fast, slower to add to the front. This isn't > specific to Clojure, it's just the way those data structures work in > any language. So conj adds the item to the front if it is conjing on > a list, to the end if is conjing on a vector. This is part of how > clojure provides a unified method of handling different type of data > structures, which are collectively called sequences in Clojure. > > On May 15, 3:36 pm, Vagif Verdi <vagif.ve...@gmail.com> wrote: > > What are the use case scenarios where one is preferable to the other > > in clojure ? > > > > It looks to me like vectors almost completely overtake lists for all > > purposes. > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
