Re: was there a time when clojure empty seqs were falsy?
I talked about the history of lazy-seq and friends at the EuroClojure 2012: http://vimeo.com/channels/357487/45561410 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.
Re: was there a time when clojure empty seqs were falsy?
I see... thanks a lot! :-) Jim On 25/02/13 12:34, David Powell wrote: Some time before the release of Clojure 1.0, there didn't used to be any such thing as an empty sequence. You either had a (lazy) sequence, or nil. This made it easy to use sequences as emptiness tests, but had the cost that a lazy sequence wasn't fully lazy because anything that returned one had to attempt to evaluate the first item in order to determine whether there was anything to return or not. [ There are some obsolete notes describing the change here: http://clojure.org/lazy for the historically curious. Or perhaps here: http://clojure.org/lazier (And the 'streams' referred to in those docs refer to this failed experiment: http://clojure.org/streams). Basically lazy-cons was replaced by lazy-seq. ] -- Dave -- -- 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. -- -- 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.
Re: was there a time when clojure empty seqs were falsy?
Some time before the release of Clojure 1.0, there didn't used to be any such thing as an empty sequence. You either had a (lazy) sequence, or nil. This made it easy to use sequences as emptiness tests, but had the cost that a lazy sequence wasn't fully lazy because anything that returned one had to attempt to evaluate the first item in order to determine whether there was anything to return or not. [ There are some obsolete notes describing the change here: http://clojure.org/lazy for the historically curious. Or perhaps here: http://clojure.org/lazier (And the 'streams' referred to in those docs refer to this failed experiment: http://clojure.org/streams). Basically lazy-cons was replaced by lazy-seq. ] -- Dave -- -- 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.
