Kevin Livingston <kevinlivingston.pub...@gmail.com> writes: >> Not at all. next is basically #(seq (rest %)); you might want to use >> it when the extra bit of strictness is beneficial to your code and you >> shouldn't use it when it isn't. > > oh, ok. I saw some posts on using the new super-lazy lists / code and > it implied that next was necessary over rest, but I didn't quite read > it in excruciating detail.
Likely what you were reading was referring to nil-punning. In very early versions of Clojure, empty seqs were nil, so you could do: (when some-seq ...) Of course this has the problem that you can't have a completely lazy seq, the first element is always evaluated (to see whether the seq is empty or not in order to return nil). They were made fully lazy by introducing empty seqs, thus you now need to explicitly check with one is empty use 'seq. So next is a shorthand for doing this on rest and replacing instances of rest with next in old code that relied on nil-punning was a simple way to upgrade. -- 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
