Hi, A sequence may be (and commonly is) lazy. Sequences on collections, strings, arrays are not lazy. Nor are those built with cons. Some sequences even have a fast (O(1)) count (eg lists, sequences on strings...) However you sould assume the worst case which is a traversal of the whole sequences -- plus if the sequence is lazy (and not yet realized) the traversal will cause its realization.
hth, Christophe On Fri, Nov 2, 2012 at 1:34 PM, Satoru Logic <satorulo...@gmail.com> wrote: > Hi, all. > > I read the following description of `sequence` in the book <Clojure > Programming>: > > * Obtaining the length of a seq carries a cost. > * The contents of sequences may be computed lazily and actually > realized only when the value involved are accessed. > > So a sequence is something lazy, right? > > I take it that if we don't do something like `(count a-seq)`, contents of > `a-seq` would not get realized. > > Then if `seq` is already "lazy", what does `lazy-seq` mean? > > -- > 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 -- Professional: http://cgrand.net/ (fr) On Clojure: http://clj-me.cgrand.net/ (en) -- 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
