Actually, I'd say seqs are very much *unlike* iterators in other languages (Java in particular).
Iterators - stateful cursors that conflate iteration with a check for whether more elements exist Seqs - immutable persistent views of a collection that separate iteration from checking for more elements http://clojure.org/sequences On Sunday, December 1, 2013 6:22:57 PM UTC-6, James Reeves wrote: > > Seqs in Clojure are very much like iterators in other languages. They're > an abstraction for navigating a sequential data structure. > > Also because values in Clojure are immutable, you rarely, if at all, > encounter situations where those objects need to be copied. Why would you, > when you can just reference the original object, secure in the knowledge > that its value cannot change. > > - James > > > On 1 December 2013 20:15, Andy Smith <[email protected]<javascript:> > > wrote: > >> Can a seq be thought of as a kind of a list of pointers to the original >> vector elements then? If so, then does an operation on a vector, (e.g. >> reverse), cause clojure to internally generate a seq of pointers to the >> original vector elements? In other words seqs seem to provide a layer of >> indirection to avoid the need to copy elements of the original collection? >> >> >> On Saturday, 30 November 2013 21:31:34 UTC, Jim foo.bar wrote: >> >>> On Sat, 30 Nov 2013 13:15:33 -0800 (PST) >>> Andy Smith <[email protected]> wrote: >>> >>> > but >>> > my question is really about the more general case of any function >>> > that manipulates a vector e.g. the following also returns a list >>> > rather than a vector as desired, >>> >>> In Clojure you rarely have to worry about types. All the >>> data-structures fall under a common set of abstractions and in >>> particular the ISeq interface. Strictly speaking map returns a seq not >>> a list. In fact a lazy seq...this is by design so further operations >>> can be applied lazily later...if you use eager operations like mapv >>> exclusively you lose the ability to aggregate operations without cost. >>> hope that clarifies it... >>> >>> >>> Jim >>> >> -- >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to [email protected]<javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> [email protected] <javascript:> >> 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 [email protected] <javascript:>. >> 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 [email protected] Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to [email protected] 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 [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
