On Nov 10, 2010, at 11:16 AM, Meikel Brandmeyer wrote: > Hi, > > On 10 Nov., 17:09, Gary Poster <gary.pos...@gmail.com> wrote: > >> I believe that the cost of having developers remember both rseq and reverse >> (why can't reverse just DTRT if it is given a vector?), last and peek >> (same), butlast and pop (same), and nth and get (same) is unnecessarily high. > > Ehm. No. > > rseq O(1), reverse O(n). > peek O(1), last O(n). > pop O(1), butlast O(n). > get O(1), nth O(n). > > (Where O(1) might sometimes mean O(log32 n)) > > The different functions are there under different names, because they > have different performance promises.
But that's exactly my point. Why should developers have to remember to use rseq on a vector, as the first example? Why can't reverse simply be part of a protocol, so that it gives O(1) when it can? Is there *any* practical value to having reverse have O(n) performance on a vector? Clojure is advertised as a practical language (I remember reading it early in JoC, for instance), and I don't see it here. > Then peek is not equivalent to > last. For lists it is equivalent to first. OK, thank you. As I said initially, the email could have been researched better, but the larger thought is still valid, with other reasonable examples. Gary -- 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
