Hi, this highly depends on the sequence function at hand. Usually they are guaranteed to be as lazy as possible. But the are two aspects: a) sometimes you need to look ahead to actually perform the action (eg. take-while or drop-while) and b) sometimes there might be a bug in the implementation and it is not as lazy as it could be. You can't do anything about a). And b) is very unlikely but also happened in the past.
A bigger problem might be ChunkedSequences. Assume you have your promises in a vector. Then a (map deref ...) will deref ahead of the actually requested elements and you have to deliver on up to 32 promises to unblock the realisation of the map sequence. So the flatten is probably more about the datastructures introducing such a ChunkedSeq than about the flatten itself. Kind regards Meikel -- -- 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.
