On Tue, Aug 4, 2009 at 10:03 AM, Rich Hickey<richhic...@gmail.com> wrote: > > > > On Aug 4, 12:35 pm, Howard Lewis Ship <hls...@gmail.com> wrote: >> These aren't criticisms, just trying to understand this better. >> >> So assoc! etc. return a new instance of the transient? > > They return the next value of the transient. > >> Or do they >> return the same transient? > > I'm not promising that they do. > >> If they return a new instance, what >> exactly is the advantage (though, obviously there is one, from the >> transcript). > > Right. > >> If they return the same instance do you prevent the >> calling code from invoking further changes or not? >> > > This one I don't understand, you can use the return value, don't reuse > the argument. If your code is structured functionally and non- > persistently that is how it will be anyway. > >> I like the idea of restricting the transient to just the originating thread. >> >> Does this mean we'll need a reduce! > > No, reduce farms out the work to the reducing function and doesn't > create a composite data structure itself. The reducing fn might use a > transient but that's an implementation detail of it. > >> and map!, etc? > > No, map returns a sequence. > >> Would there be an >> advantage to those? Is there an intersection (or potential danger) >> between transient structures and laziness? >> > > Transient data structures should never be part of the public interface > of anything. They are just an implementation detail, an optimization, > e.g. into/vec/vector now use transients, but aren't now into!/vec!/ > vector! - the transients are inside. > > Hope that helps, > > Rich
It does, pretty much what I expected. Care to summarize why they are so much faster than persistent types (for those of us too lazy/busy to read the source)? > > > > -- Howard M. Lewis Ship Creator of Apache Tapestry Director of Open Source Technology at Formos --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
