It also might help to notice KeySeq defines first/next, but never explicitly walks the seq.
That's left to the user of the KeySeq. Thanks, Ambrose On Sun, Feb 2, 2014 at 12:18 PM, Michał Marczyk <michal.marc...@gmail.com>wrote: > On 2 February 2014 05:14, Justin Smith <noisesm...@gmail.com> wrote: > >> Pardon my ignorance but if this is producing a lazy result, how is it >> doing so? >> >> https://github.com/clojure/clojure/blob/dff9600387b962f16fc78e6477e10e34651fd366/src/jvm/clojure/lang/APersistentMap.java#L134 >> > > APersistentMap's KeySeq.create and ValSeq.create are pretty much > equivalent to (map key entry-seq) and (map val entry-seq). The logic > producing entry-seq lives in the individual map types and is indeed lazy. > > Cheers, > Michał > > >> >> On Saturday, February 1, 2014 7:54:32 PM UTC-8, Ambrose Bonnaire-Sergeant >> wrote: >> >>> zipmap could also potentially use transients (which would be a nice >>> addition). >>> >>> keys/vals are also lazy, so I would be surprised if there was any >>> performance >>> difference with walking the seq "twice". >>> >>> Thanks, >>> Ambrose >>> >>> >>> On Sun, Feb 2, 2014 at 11:35 AM, Justin Smith <noise...@gmail.com>wrote: >>> >>>> Realistically, how many situations are there where running keys and >>>> vals independently is preferable to running seq once and using the two >>>> element vectors that returns? >>>> >>>> Usually this way one can avoid walking the whole thing twice. >>>> >>>> (into {} (map (fn [[k v]] [k (inc v)]) {:a 0 :b 1})) is representative >>>> of the idiom I usually use. As a bonus, into uses transients, which can >>>> create the resulting structure in fewer cycles / less time. >>>> >>>> >>>> On Saturday, February 1, 2014 10:00:33 AM UTC-8, Sam Ritchie wrote: >>>> >>>>> Looks like Rich just chimed in with: >>>>> >>>>> "keys order == vals order == seq order " >>>>> >>>>> Matching Socks >>>>> January 31, 2014 7:31 PM >>>>> Actually, http://dev.clojure.org/jira/browse/CLJ-1302 "keys and vals >>>>> consistency not mentioned in docstring" was declined, with the comment >>>>> "The >>>>> absence of this property in the docs is correct. You should not rely on >>>>> this." >>>>> >>>>> >>>>> >>>>> On Wednesday, August 11, 2010 6:03:39 PM UTC-4, Chouser wrote: >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Clojure" group. >>>>> To post to this group, send email to clo...@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+u...@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+u...@googlegroups.com. >>>>> >>>>> For more options, visit https://groups.google.com/groups/opt_out. >>>>> >>>>> >>>>> -- >>>>> Sam Ritchie (@sritchie) >>>>> Paddleguru Co-Founder >>>>> 703.863.8561 >>>>> www.paddleguru.com >>>>> Twitter <http://twitter.com/paddleguru> // >>>>> Facebook<http://facebook.com/paddleguru> >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Clojure" group. >>>> To post to this group, send email to clo...@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+u...@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+u...@googlegroups.com. >>>> For more options, visit https://groups.google.com/groups/opt_out. >>>> >>> >>> -- >> 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/groups/opt_out. >> > > -- > 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/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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