FYI the ticket about volatile is at http://dev.clojure.org/jira/browse/CLJ-1512 and the same question was raised there.
On Mon, Sep 8, 2014 at 4:25 PM, Frantisek Sodomka <fsodo...@gmail.com> wrote: > Hello, > I posted a question about volatiles on the github commit: > https://github.com/clojure/clojure/commit/60440977823752f13a3fec3637538e9a1d68c5d4 > > I don't know if anybody noticed, so... why is volatile created with function > "volatile!" and not "volatile" ? Atoms, refs and agents don't have > exclamation mark in their constructor functions. > > Should I think about volatiles as mutable locals? :-) > > FrantiĊĦek > > > On Friday, September 5, 2014 4:26:53 PM UTC+2, Alex Miller wrote: >> >> Clojure 1.7.0-alpha1 is now available. >> >> Try it via >> - Download: >> http://central.maven.org/maven2/org/clojure/clojure/1.7.0-alpha2/ >> - Download securely: >> https://repo1.maven.org/maven2/org/clojure/clojure/1.7.0-alpha2/ >> - Leiningen: [org.clojure/clojure "1.7.0-alpha2"] >> >> Highlights below, full change log here: >> https://github.com/clojure/clojure/blob/master/changes.md >> >> For users of Clojure 1.7.0-alpha1, there have been a few important changes >> in transducers since alpha1: >> - Removed flatmap transducer >> - Added cat transducer >> - mapcat 1-arity is now a transducer, specifically: (comp (map f) cat) >> - The completing function has been lifted to be public >> >> Clojure 1.7.0-alpha2 has the changes below from 1.6.0: >> >> ## 1 New and Improved Features >> >> ### 1.1 Transducers >> >> Transducers is a new way to decouple algorithmic transformations from >> their >> application in different contexts. Transducers are functions that >> transform >> reducing functions to build up a "recipe" for transformation. >> >> Also see: http://blog.cognitect.com/blog/2014/8/6/transducers-are-coming >> >> Many existing sequence functions now have a new arity (one fewer argument >> than before). This arity will return a transducer that represents the same >> logic but is independent of lazy sequence processing. Functions included >> are: >> >> * conj (conjs to []) >> * map >> * mapcat >> * filter >> * remove >> * take >> * take-while >> * drop >> * drop-while >> * cycle >> * take-nth >> * replace >> * partition-by >> * partition-all >> * keep >> * keep-indexed >> >> Additionally some new transducer functions have been added: >> >> * cat - concatenates the contents of each input >> * de-dupe - removes consecutive duplicated values >> * random-sample - returns items from coll with random probability >> >> And this function can be used to make completing transforms: >> >> * completing >> >> There are also several new or modified functions that can be used to apply >> transducers in different ways: >> >> * sequence - takes a transformation and a coll and produces a lazy seq >> * transduce - reduce with a transformation (eager) >> * iteration - returns an iterable/seqable/reducible seq of applications of >> the transducer to items in coll. Applications are re-performed with every >> iterator/seq/reduce. >> * run! - run the transformation for side effects on the collection >> >> There have been a number of internal changes to support transducers: >> >> * volatiles - there are a new set of functions (volatile!, vswap!, >> vreset!, volatile?) to create and use volatile "boxes" to hold state in >> stateful transducers. Volatiles are faster than atoms but give up atomicity >> guarantees so should only be used with thread isolation. >> * array iterators - added support for iterators over arrays >> >> Some issues created and addressed during development: >> * [CLJ-1511](http://dev.clojure.org/jira/browse/CLJ-1511) >> * [CLJ-1497](http://dev.clojure.org/jira/browse/CLJ-1497) >> >> ### 1.2 Keyword and Symbol Construction >> >> In response to issues raised in >> [CLJ-1439](http://dev.clojure.org/jira/browse/CLJ-1439), >> several changes have been made in symbol and keyword construction: >> >> 1) The main bottleneck in construction of symbols (which also occurs >> inside keywords) was >> interning of the name and namespace strings. This interning has been >> removed, resulting >> in a performance increase. >> >> 2) Keywords are cached and keyword construction includes a cache check. A >> change was made >> to only clear the cache reference queue when there is a cache miss. >> >> ### 1.3 Warn on Boxed Math >> >> One source of performance issues is the (unintended) use of arithmetic >> operations on >> boxed numbers. To make detecting the presence of boxed math easier, a >> warning will now >> be emitted about boxed math if \*unchecked-math* is enabled. >> >> Example use: >> >> user> (defn plus-2 [x] (+ x 2)) ;; no warning, but boxed >> #'user/plus-2 >> user> (set! *unchecked-math* true) >> true >> user> (defn plus-2 [x] (+ x 2)) ;; now we see a warning >> Boxed math warning, NO_SOURCE_PATH:10:18 - call: public static >> java.lang.Number >> clojure.lang.Numbers.unchecked_add(java.lang.Object,long). >> #'user/plus-2 >> user> (defn plus-2 [^long x] (+ x 2)) ;; use a hint to avoid boxing >> #'user/plus-2 >> >> * [CLJ-1325](http://dev.clojure.org/jira/browse/CLJ-1325) >> >> ### 1.4 update - like update-in for first level >> >> `update` is a new function that is like update-in specifically for >> first-level keys: >> >> (update m k f args...) >> >> Example use: >> >> user> (update {:a 1} :a inc) >> {:a 2} >> user> (update {:a 1} :a + 2) >> {:a 3} >> user> (update {} :a identity) ;; missing returns nil >> {:a nil} >> >> * [CLJ-1251](http://dev.clojure.org/jira/browse/CLJ-1251) >> >> ## 2 Enhancements >> >> ### 2.1 Error messages >> >> * [CLJ-1261](http://dev.clojure.org/jira/browse/CLJ-1261) >> Invalid defrecord results in exception attributed to consuming ns >> instead of defrecord ns >> * [CLJ-1169](http://dev.clojure.org/jira/browse/CLJ-1169) >> Report line,column, and source in defmacro errors >> >> ### 2.2 Documentation strings >> >> No changes. >> >> ### 2.3 Performance >> >> * [CLJ-1430](http://dev.clojure.org/jira/browse/CLJ-1430) >> Improve performance of partial with more unrolling >> * [CLJ-1384](http://dev.clojure.org/jira/browse/CLJ-1384) >> clojure.core/set should use transients for better performance >> * [CLJ-1429](http://dev.clojure.org/jira/browse/CLJ-1429) >> Cache unknown multimethod value default dispatch >> >> ### 2.4 Other enhancements >> >> * [CLJ-1191](http://dev.clojure.org/jira/browse/CLJ-1191) >> Improve apropos to show some indication of namespace of symbols found >> * [CLJ-1378](http://dev.clojure.org/jira/browse/CLJ-1378) >> Hints don't work with #() form of function >> * [CLJ-1498](http://dev.clojure.org/jira/browse/CLJ-1498) >> Removes owner-thread check from transients - this check was preventing >> some valid usage of transients in core.async where a transient is created on >> one thread and then used again in another pooled thread (while still >> maintaining thread isolation). >> >> ## 3 Bug Fixes >> >> * [CLJ-1362](http://dev.clojure.org/jira/browse/CLJ-1362) >> Reduce broken on some primitive vectors >> * [CLJ-1388](http://dev.clojure.org/jira/browse/CLJ-1388) >> Equality bug on records created with nested calls to map->record >> * [CLJ-1274](http://dev.clojure.org/jira/browse/CLJ-1274) >> Unable to set compiler options via system properties except for AOT >> compilation >> * [CLJ-1241](http://dev.clojure.org/jira/browse/CLJ-1241) >> NPE when AOTing overrided clojure.core functions >> * [CLJ-1185](http://dev.clojure.org/jira/browse/CLJ-1185) >> reductions does not check for reduced value >> * [CLJ-1039](http://dev.clojure.org/jira/browse/CLJ-1039) >> Using def with metadata {:type :anything} throws ClassCastException >> during printing >> * [CLJ-887](http://dev.clojure.org/jira/browse/CLJ-887) >> Error when calling primitive functions with destructuring in the arg >> vector >> * [CLJ-823](http://dev.clojure.org/jira/browse/CLJ-823) >> Piping seque into seque can deadlock >> * [CLJ-738](http://dev.clojure.org/jira/browse/CLJ-738) >> <= is incorrect when args include Double/NaN > > -- > 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/d/optout. -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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