I don't understand what you mean. '(range 1000)' produces a lazy sequence, and '(reduce + ...)' doesn't hold onto the head of the lazy sequence. Therefore, each element can be GC'd as soon as added into the running total, the the lazy sequence only produces new elements as they are requested by the reduction (chunking aside, of course). Alan
On Tue, May 10, 2016 at 4:14 PM, JvJ <kfjwhee...@gmail.com> wrote: > That brings me to another thing I've wondered about. It is a typical > clojure idiom to do something like (reduce + (range 1000)). > > But, unlike imperative loops, this will cache all those 1000 elements. > This can kind of bloat memory, especially with large sequences? > > How can you get around it (other than tail-recursion or the while > construction)? > > On Tuesday, 10 May 2016 09:45:50 UTC-7, Alex Miller wrote: >> >> Because some of the time you don't want caching. For example, if you want >> to (later) reduce over a large (larger than memory even) external resource. >> eductions allow you to define the source in one spot but defer the (eager) >> reduction until later. >> >> On Tuesday, May 10, 2016 at 11:22:24 AM UTC-5, JvJ wrote: >>> >>> In that case, why aren't eductions just lazy sequences? >>> >>> On Monday, 9 May 2016 16:07:55 UTC-7, Alex Miller wrote: >>>> >>>> eductions are non-caching (will re-perform their work each time they >>>> are used), so most of the time I would say lazy sequences are preferable. >>>> >>>> On Monday, May 9, 2016 at 4:54:48 PM UTC-5, JvJ wrote: >>>>> >>>>> In a similar vein, do you think that eductions are generally a better >>>>> idea than lazy sequences/for comprehensions? >>>>> >>>>>> >>>>>> -- > 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.
