Obviously, that should say: Clojure 1.7.0-alpha2 is now available.
On Friday, September 5, 2014 9:27:06 AM UTC-5, 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. 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