I find the current behaviour to be perfectly intuitive. I think it would be unnecessarily complex and confusing to have seqs behave differently depending on what data structure they were originally derived from.
- James On 9 September 2016 at 11:23, Colin Yates <colin.ya...@gmail.com> wrote: > Hi all, > > So in the spirit of exposing my ignorance to the internet :-), I have just > been bitten by a bug due to the behaviour of the core libraries which I > find really surprising: > > (def v [1 2 3]) > (conj v 4) => [1 2 3 4] > (conj (map identity v) 4) => (4 1 2 3) > (conj (remove (constantly false) v) 4) => (4 1 2 3) > (conj (filter identity v) 4) => (4 1 2 3) > > In other words, I was relying on map, remove and filter preserving the > semantics (other than laziness) of the structure of the input, give it a > vector and you get a vector-like lazy sequence. This turns out not to be > the case. > > Now, I know there is mapv which returns a vector but why isn't there a > removev and a filterv etc.? > > What makes it more onerous for me is the fact conj states that its > behaviour differs depending on the concrete type, which is great, but how > am I supposed to know which concrete type is returned from > map|filter|remove? My assumption was it would be semantically equivalent to > the input (i.e. a vector in this case). > > The reason I have dodged this is because I don't frequently rely on vector > semantics but I am surprised this isn't better documented? > > Is it me? > > Thanks, > > Colin > > -- > 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.
