Clojure 1.7.0-alpha6 is now available. Try it via - Download: https://repo1.maven.org/maven2/org/clojure/clojure/1.7.0-alpha6/ - Leiningen: [org.clojure/clojure "1.7.0-alpha6"]
Regression fixes from previous alphas (and one from 1.6): 1) CLJ-1544 was rolled back and will be investigated for a future release. 2) CLJ-1637 fixed regression with vec on MapEntry 3) CLJ-1663 fixed regression in classloader (affected Cursive) 4) CLJ-1638 fixed regression with removed PersistentVector.create(List) method 5) CLJ-1681 fixed regression in 1.6 with NPE on reflection warning for literal nil arg 6) CLJ-1604 fixed problem with AOT and shadowing clojure.core symbols that prevented update Some highlights new in alpha6: ## Transducer-related changes: The LazyTransformer introduced to create lazy transforming sequences has been replaced with a TransformingIterator. This was done to simplify the code around transformations and to make certain use cases around eduction more efficient. ## Faster reduce, iterator, and sequence paths A lot of work has been done across a set of tickets to improve the ability of collections to provide more efficient reduce or iterator performance, and also to make common sequence generators create faster sequence and reduce paths. You should see significant performance in many reduce-related paths (this includes reduce, transduce, into, and anything else built on reduce). Many of those changes also have beneficial sequence performance, so you may see some benefits even in code that does not use transducers. * Most uses of SeqIterator have now been replaced with iterators that directly walk the underlying source for improved efficiency. This includes maps, sets, records, etc. * repeat - now returns a faster sequence with a fast reduce path * cycle - now returns a faster sequence with a fast reduce path * iterate - now returns a faster sequence with a fast reduce path * range - (did not quite make it in, but coming soon...) * keys - iterates directly over the keys of a map, without seq or MapEntry allocation * vals - iterates directly over the vals of a map, without seq or MapEntry allocation * iterator-seq - now creates a chunked sequence when previously it was unchunked * vec and set - were not changed in this release but were set up in a previous alpha to take advantage of the reduce and iterator changes above ## Reader conditionals Reader Conditionals is a new capability to support portable code that can run on multiple Clojure platforms with only small changes. In particular, this feature aims to support the increasingly common case of libraries targeting both Clojure and ClojureScript. Code intended to be common across multiple platforms should use a new supported file extension: ".cljc". When requested to load a namespace, the platform-specific file extension (.clj, .cljs) will be checked prior to .cljc. A new reader form can be used to specify "reader conditional" code in cljc files (and *only* cljc files). Each platform defines a feature identifying the platform (:clj, :cljs, :cljr). The reader conditional specifies code that is read conditionally based on the feature/ Form #? takes a list of alternating feature and expression. These are checked like cond and the selected expression is read and returned. Other branches are unread. If no branch is selected, the reader reads nothing (not nil, but literally as if reading ""). An optional ":default" branch can be used as a fallthrough. Reader conditional with 2 features and a default: #?(:clj Double/NaN :cljs js/NaN :default nil) There is also a reader conditional splicing form. The evaluated expression should be sequential and will be spliced into the surrounded code, similar to unqoute-splicing. For example: [1 2 #?@(:clj [3 4] :cljs [5 6])] This form would read as [1 2 3 4] on Clojure, [1 2 5 6] on ClojureScript, and [1 2] on any other platform. Additionally, the reader can now be invoked with options for the features to use and how to interpret reader conditionals. By default, reader conditionals are not allowed, but that can be turned on, or a "preserve" mode can be used to preserve all branches (most likely useful for tooling or source transforms). In the preserve mode, the reader conditional itself and any tagged literals within the unselected branches are returned as tagged literal data. For more information, see: http://dev.clojure.org/display/design/Reader+Conditionals Two important side notes: - Clojure dependencies have been updated and you must re-run antsetup.sh if you build Clojure locally with ant. - The equivalent ClojureScript support for reader conditionals is not yet available but is a top priority to release as soon as possible... stay tuned. ## Printing as data There have been enhancements in how the REPL prints values without a print-method, specifically Throwable and the fallthrough Object case. Both cases now print in a tagged literal data form that can be read by the reader. Unhandled objects print with the class, hash code, and toString: user=> *ns* #object[clojure.lang.Namespace 0x55aa628 "user"] Thrown exceptions will still be printed in the normal way by the default REPL but printing them to a stream will show a different form: user=> (/ 1 0) ArithmeticException Divide by zero clojure.lang.Numbers.divide (Numbers.java:158) user=> (println *e) #error{:cause Divide by zero, :via [{:type java.lang.ArithmeticException, :message Divide by zero, :at [clojure.lang.Numbers divide Numbers.java 158]}], :trace [[clojure.lang.Numbers divide Numbers.java 158] [clojure.lang.Numbers divide Numbers.java 3808] [user$eval5 invoke NO_SOURCE_FILE 3] ;; elided ... ]]} For all changes new in alpha6, see the issues marked "(alpha6)" in the full changes below. ------------------------------------------------------------ Clojure 1.7.0-alpha6 has the following updates since 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://clojure.org/transducers 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 * take-nth * replace * partition-by * partition-all * keep * keep-indexed * map-indexed * distinct * interpose Additionally some new transducer functions have been added: * cat - concatenates the contents of each input * dedupe - 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) * eduction - returns a reducible/iterable of applications of the transducer to items in coll. Applications are re-performed with every reduce/iterator. * 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 related issues addressed during development: * [CLJ-1511](http://dev.clojure.org/jira/browse/CLJ-1511) * [CLJ-1497](http://dev.clojure.org/jira/browse/CLJ-1497) * [CLJ-1549](http://dev.clojure.org/jira/browse/CLJ-1549) * [CLJ-1537](http://dev.clojure.org/jira/browse/CLJ-1537) * [CLJ-1554](http://dev.clojure.org/jira/browse/CLJ-1554) * [CLJ-1601](http://dev.clojure.org/jira/browse/CLJ-1601) * [CLJ-1606](http://dev.clojure.org/jira/browse/CLJ-1606) * [CLJ-1621](http://dev.clojure.org/jira/browse/CLJ-1621) * [CLJ-1600](http://dev.clojure.org/jira/browse/CLJ-1600) * [CLJ-1635](http://dev.clojure.org/jira/browse/CLJ-1635) (alpha6) * [CLJ-1683](http://dev.clojure.org/jira/browse/CLJ-1683) (alpha6) * [CLJ-1669](http://dev.clojure.org/jira/browse/CLJ-1669) (alpha6) ### 1.2 Reader Conditionals (alpha6) Reader Conditionals is a new capability to support portable code that can run on multiple Clojure platforms with only small changes. In particular, this feature aims to support the increasingly common case of libraries targeting both Clojure and ClojureScript. Code intended to be common across multiple platforms should use a new supported file extension: ".cljc". When requested to load a namespace, the platform-specific file extension (.clj, .cljs) will be checked prior to .cljc. A new reader form can be used to specify "reader conditional" code in cljc files (and *only* cljc files). Each platform defines a feature identifying the platform (:clj, :cljs, :cljr). The reader conditional specifies code that is read conditionally based on the feature/ Form #? takes a list of alternating feature and expression. These are checked like cond and the selected expression is read and returned. Other branches are unread. If no branch is selected, the reader reads nothing (not nil, but literally as if reading ""). An optional ":default" branch can be used as a fallthrough. Reader conditional with 2 features and a default: #?(:clj Double/NaN :cljs js/NaN :default nil) There is also a reader conditional splicing form. The evaluated expression should be sequential and will be spliced into the surrounded code, similar to unqoute-splicing. For example: [1 2 #?@(:clj [3 4] :cljs [5 6])] This form would read as [1 2 3 4] on Clojure, [1 2 5 6] on ClojureScript, and [1 2] on any other platform. Additionally, the reader can now be invoked with options for the features to use and how to interpret reader conditionals. By default, reader conditionals are not allowed, but that can be turned on, or a "preserve" mode can be used to preserve all branches (most likely useful for tooling or source transforms). In the preserve mode, the reader conditional itself and any tagged literals within the unselected branches are returned as tagged literal data. For more information, see: http://dev.clojure.org/display/design/Reader+Conditionals * [CLJ-1424](http://dev.clojure.org/jira/browse/CLJ-1424) ### 1.3 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. ### 1.4 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 set to :warn-on-boxed (any truthy value will enable unchecked-math, only this specific value enables the warning). Example use: user> (defn plus-2 [x] (+ x 2)) ;; no warning, but boxed #'user/plus-2 user> (set! *unchecked-math* :warn-on-boxed) 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) * [CLJ-1535](http://dev.clojure.org/jira/browse/CLJ-1535) * [CLJ-1642](http://dev.clojure.org/jira/browse/CLJ-1642) (alpha6) ### 1.5 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) ### 1.6 Faster reduce and iterator paths (alpha6) Several important Clojure functions now return sequences that also contain fast reduce() (or in some cases iterator()) paths. In many cases, the new implementations are also faster for lazy sequences * repeat - now implements IReduce * cycle - implements IReduceInit * iterate - implements IReduceInit * range - implements IReduce, specialized case handles common case of all longs * keys - iterates directly over the keys of a map, without seq or MapEntry allocation * vals - iterates directly over the vals of a map, without seq or MapEntry allocation * iterator-seq - creates a chunked sequence when previously it was unchunked Additionally, hash-maps and hash-sets now provide iterators that walk the data structure directly rather than via a sequence. A new interface (IMapIterable) for direct key and val iterators on maps was added. External data structures can use this interface to provide direct key and val iterators via keys and vals. These enhancements are particularly effective when used in tandem with transducers via transduce, sequence, into, and eduction. * [CLJ-1603](http://dev.clojure.org/jira/browse/CLJ-1603) * [CLJ-1515](http://dev.clojure.org/jira/browse/CLJ-1515) * [CLJ-1602](http://dev.clojure.org/jira/browse/CLJ-1602) * [CLJ-1669](http://dev.clojure.org/jira/browse/CLJ-1669) ### 1.7 Printing as data (alpha6) There have been enhancements in how the REPL prints values without a print-method, specifically Throwable and the fallthrough Object case. Both cases now print in a tagged literal data form that can be read by the reader. Unhandled objects print with the class, hash code, and toString: user=> *ns* #object[clojure.lang.Namespace 0x55aa628 "user"] Thrown exceptions will still be printed in the normal way by the default REPL but printing them to a stream will show a different form: user=> (/ 1 0) ArithmeticException Divide by zero clojure.lang.Numbers.divide (Numbers.java:158) user=> (println *e) #error{:cause Divide by zero, :via [{:type java.lang.ArithmeticException, :message Divide by zero, :at [clojure.lang.Numbers divide Numbers.java 158]}], :trace [[clojure.lang.Numbers divide Numbers.java 158] [clojure.lang.Numbers divide Numbers.java 3808] [user$eval5 invoke NO_SOURCE_FILE 3] ;; elided ... ]]} ## 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 * [CLJ-1297](http://dev.clojure.org/jira/browse/CLJ-1297) Give more specific hint if namespace with "-" not found to check file uses "_" ### 2.2 Documentation strings * [CLJ-1417](http://dev.clojure.org/jira/browse/CLJ-1417) clojure.java.io/input-stream has incorrect docstring * [CLJ-1357](http://dev.clojure.org/jira/browse/CLJ-1357) Fix typo in gen-class doc-string * [CLJ-1479](http://dev.clojure.org/jira/browse/CLJ-1479) Fix typo in filterv example * [CLJ-1480](http://dev.clojure.org/jira/browse/CLJ-1480) Fix typo in defmulti docstring * [CLJ-1477](http://dev.clojure.org/jira/browse/CLJ-1477) Fix typo in deftype docstring * [CLJ-1478](http://dev.clojure.org/jira/browse/CLJ-1378) Fix typo in clojure.main usage ### 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 * [CLJ-1529](http://dev.clojure.org/jira/browse/CLJ-1529) Reduce compile times by avoiding unnecessary calls to Class.forName() * [CLJ-1546](http://dev.clojure.org/jira/browse/CLJ-1546) vec is now faster on almost all inputs * [CLJ-1618](http://dev.clojure.org/jira/browse/CLJ-1618) set is now faster on almost all inputs ### 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). * [CLJ-803](http://dev.clojure.org/jira/browse/CLJ-803) Extracted IAtom interface implemented by Atom. * [CLJ-1315](http://dev.clojure.org/jira/browse/CLJ-1315) Don't initialize classes when importing them * [CLJ-1330](http://dev.clojure.org/jira/browse/CLJ-1330) Class name clash between top-level functions and defn'ed ones * [CLJ-1349](http://dev.clojure.org/jira/browse/CLJ-1349) Update to latest test.generative and add dependency on test.check * [CLJ-1546](http://dev.clojure.org/jira/browse/CLJ-1546) vec now works with things that only implement Iterable or IReduceInit * [CLJ-1618](http://dev.clojure.org/jira/browse/CLJ-1618) set now works with things that only implement Iterable or IReduceInit * [CLJ-1633](http://dev.clojure.org/jira/browse/CLJ-1633) PersistentList/creator doesn't handle ArraySeqs correctly * [CLJ-1589](http://dev.clojure.org/jira/browse/CLJ-1589) (alpha6) Clean up unused paths in InternalReduce * [CLJ-1677](http://dev.clojure.org/jira/browse/CLJ-1677) (alpha6) Add setLineNumber() to LineNumberingPushbackReader * [CLJ-1667](http://dev.clojure.org/jira/browse/CLJ-1667) (alpha6) Change test to avoid using hard-coded socket port * [CLJ-1683](http://dev.clojure.org/jira/browse/CLJ-1683) (alpha6) Change reduce tests to better catch reduce without init bugs ## 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 * [CLJ-1408](http://dev.clojure.org/jira/browse/CLJ-1408) Make cached string value of Keyword and Symbol transient * [CLJ-1466](http://dev.clojure.org/jira/browse/CLJ-1466) clojure.core/bean should implement Iterable * [CLJ-1578](http://dev.clojure.org/jira/browse/CLJ-1578) Make refer of Clojure core function not throw exception on reload * [CLJ-1501](http://dev.clojure.org/jira/browse/CLJ-1501) LazySeq equals() should not use equiv() logic * [CLJ-1572](http://dev.clojure.org/jira/browse/CLJ-1572) into (and other fns that rely on reduce) require only IReduceInit * [CLJ-1619](http://dev.clojure.org/jira/browse/CLJ-1619) PersistentVector now directly implements reduce without init * [CLJ-1580](http://dev.clojure.org/jira/browse/CLJ-1580) Transient collections should guarantee thread visibility * [CLJ-1590](http://dev.clojure.org/jira/browse/CLJ-1590) Some IReduce/IReduceInit implementors don't respect reduced * [CLJ-979](http://dev.clojure.org/jira/browse/CLJ-979) Clojure resolves to wrong deftype classes when AOT compiling or reloading * [CLJ-1636](http://dev.clojure.org/jira/browse/CLJ-1636) (alpha6) Fix intermittent SeqIterator problem by removing use of this as a sentinel * [CLJ-1637](http://dev.clojure.org/jira/browse/CLJ-1636) (alpha6) Fix regression from CLJ-1546 that broke vec on MapEntry * [CLJ-1663](http://dev.clojure.org/jira/browse/CLJ-1663) (alpha6) Fix regression from CLJ-979 for DynamicClassLoader classloader delegation * [CLJ-1604](http://dev.clojure.org/jira/browse/CLJ-1604) (alpha6) Fix error from AOT'ed code defining a var with a clojure.core symbol name * [CLJ-1561](http://dev.clojure.org/jira/browse/CLJ-1561) (alpha6) Fix incorrect line number reporting for error locations * [CLJ-1568](http://dev.clojure.org/jira/browse/CLJ-1568) (alpha6) Fix incorrect line number reporting for error locations * [CLJ-1638](http://dev.clojure.org/jira/browse/CLJ-1638) (alpha6) Fix regression from CLJ-1546 removed PersistentVector.create(List) method * [CLJ-1681](http://dev.clojure.org/jira/browse/CLJ-1681) (alpha6) Fix regression from CLJ-1248 (1.6) in reflection warning with literal nil argument -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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