Clojure 1.6 正式版发布，并发编程语言

Lisp 是一种编程语言，以表达性和功能强大著称，但人们通常认为它不太适合应用于一般情况。Clojure 是一种运行在 Java™ 平台上的 Lisp 方言，它的出现彻底改变了这一现状。如今，在任何具备 Java 虚拟机的地方，您都可以利用 Lisp 的强大功能。

作为当今最主流的运算平台JVM，把函数式编程语言引入JVM也是很多人尝试的方向，Clojure就是其中之一。Clojure是一个在JVM平台运行的动态函数式编程语言，其语法接近于LISP语言，在JVM平台运行的时候，会被编译为JVM的字节码进行运算。

Clojure保持了函数式语言的主要特点，例如immutable state，Full Lisp-style macro support，persistent data structures等等，并且还能够非常方便的调用Java类库的API，和Java类库进行良好的整合。

Clojure 1.6 正式版发布，下载地址：http://clojure.org/downloads

此版本更新内容如下：

1 兼容性和依赖关系

1.1 JDK 版本更新

Clojure now builds with Java SE 1.6 and emits bytecode requiring Java SE 1.6 instead of Java SE 1.5. [CLJ-1268]

1.2 ASM 库更新

The embedded version of the ASM bytecode library has been upgraded to ASM 4.1. [CLJ-713]

1.3 提升 "Alpha" 特性

The following features are no longer marked Alpha in Clojure:

• Watches - add-watch, remove-watch

• Transients - transient, persistent!, conj!, assoc!, dissoc!, pop!, disj!

• Exception data - ex-info, ex-data

• Promises - promise, deliver

• Records - defrecord

• Types - deftype

• Pretty-print tables - print-table

2 新特性和改进记录

2.1 Java API

2.2 Map destructuring extended to support namespaced keys
2.3 New "some" operations
2.4 Hashing

Related tickets for dev and regressions:

• CLJ-1328Make several Clojure tests independent of ordering

• CLJ-1331Update primitive vectors to use Murmur3 hash

• CLJ-1335Update hash for empty PersistentList and LazySeq

• CLJ-1336Make hashing mixing functions available in Clojure

• CLJ-1338Make Murmur3 class public

• CLJ-1344Update mapHasheq to call Murmur3 algorithm

• CLJ-1348Add hash-ordered-coll and hash-unordered-coll

• CLJ-1355Restore cached hashCode for Symbol and (uncached) hashCode for Keyword

• CLJ-1365Add type hints for new collection hash functions

2.5 bitops

• CLJ-827 - unsigned-bit-shift-right

2.6 clojure.test

• CLJ-866 - test-vars

• CLJ-1352 - fix regression in CLJ-866

3 功能增强

3.1 Printing

• CLJ-908Print metadata for functions when print-meta is true and remove errant space at beginning.

• CLJ-937pprint cl-format now supports E, F, and G formats for ratios.

3.2 错误信息

• CLJ-1248Include type information in reflection warning messages

• CLJ-1099If non-seq passed where seq is needed, error message now is an ExceptionInfo with the instance value, retrievable via ex-data.

• CLJ-1083Fix error message reporting for "munged" function names (like a->b).

• CLJ-1056Handle more cases and improve error message for errors in defprotocol definitions.

• CLJ-1102Better handling of exceptions with empty stack traces.

• CLJ-939Exceptions thrown in the top level ns form are reported without file or line number.

3.3 文档字符串

• CLJ-1164Fix typos in clojure.instant/validated and other internal instant functions.

• CLJ-1143Correct doc string for ns macro.

• CLJ-196Clarify value of file is undefined in the REPL.

• CLJ-1228Fix a number of spelling errors in namespace and doc strings.

• CLJ-835Update defmulti doc to clarify expectations for hierarchy argument.

• CLJ-1304Fix minor typos in documentation and comments

• CLJ-1302Mention that keys and vals order are consistent with seq order

3.4 性能

• CLJ-858Improve speed of STM by removing System.currentTimeMillis.

• CLJ-669clojure.java.io/do-copy: use java.nio for Files

• commitReduce overhead of protocol callsites by removing unneeded generated cache fields.

3.5 其他改进

• CLJ-908Make default-data-reader-fn set!-able in REPL, similar to data-readers.

• CLJ-783Make clojure.inspector/inspect-tree work on sets.

• CLJ-896Make browse-url aware of xdg-open.

• CLJ-1160Fix clojure.core.reducers/mapcat does not stop on reduced? values.

• CLJ-1121-> and ->> have been rewritten to work with a broader set of macros.

• CLJ-1105clojure.walk now supports records.

• CLJ-949Removed all unnecessary cases of sneakyThrow.

• CLJ-1238Allow EdnReader to read foo// (matches LispReader behavior).

• CLJ-1264Remove uses of _ as a var in the Java code (causes warning in Java 8).

• CLJ-394Add record? predicate.

• CLJ-1200ArraySeq dead code cleanup, ArraySeq_short support added.

• CLJ-1331Primitive vectors should implement hasheq and use new hash algorithm

• CLJ-1354Make APersistentVector.SubVector public so other collections can access

• CLJ-1353Make awt run headless during the build process

4 Bug 修复

• CLJ-1018Make range consistently return infinite sequence of start with a step of 0.

• CLJ-863Make interleave return () on 0 args and identity on 1 args.

• CLJ-1072Update internal usages of the old metadata reader syntax to new syntax.

• CLJ-1193Make bigint and biginteger functions work on double values outside long range.

• CLJ-1154Make Compile.java flush but not close stdout so errors can be reported.

• CLJ-1161Remove bad version.properties from sources jar.

• CLJ-1175Fix invalid behavior of Delay/deref if an exception is thrown - exception will now be rethrown on subsequent calls and not enter a corrupted state.

• CLJ-1171Fix several issues with instance? to make it consistent when used with apply.

• CLJ-1202Protocol fns with dashes may get incorrectly compiled into field accesses.

• CLJ-850Add check to emit invokePrim with return type of double or long if type-hinted.

• CLJ-1177clojure.java.io URL to File coercion corrupts path containing UTF-8 characters.

• CLJ-1234Accept whitespace in Record and Type reader forms (similar to data literals).

• CLJ-1233Allow ** as a valid symbol name without triggering dynamic warnings.

• CLJ-1246Add support to clojure.reflect for classes with annotations.

  • CLJ-1184Evaling #{do ...} or [do ...] is treated as do special form.

• CLJ-1090Indirect function calls through Var instances fail to clear locals.

• CLJ-1076pprint tests fail on Windows, expecting \n.

• CLJ-766Make into-array work consistently with short-array and byte-array on bigger types.

• CLJ-1285Data structure invariants are violated after persistent operations when collision node created by transients.

• CLJ-1222Multiplication overflow issues around Long/MIN_VALUE

• CLJ-1118Inconsistent numeric comparison semantics between BigDecimals and other numerics

• CLJ-1125Clojure can leak memory in a servlet container when using dynamic bindings or STM transactions.

• CLJ-1082Subvecs of primitve vectors cannot be reduced

• CLJ-1301Case expressions use a mixture of hashCode and hasheq, potentially leading to missed case matches when these differ.

• CLJ-983proxy-super does not restore original binding if call throws exception

• CLJ-1176clojure.repl/source errors when read-eval bound to :unknown

• CLJ-935clojure.string/trim uses different definition of whitespace than triml and trimr

• CLJ-1058StackOverflowError on exception in reducef for PersistentHashMap fold

• CLJ-1328Fix some tests in the Clojure test suite to make their names unique and independent of hashing order

• CLJ-1339Empty primitive vectors throw NPE on .equals with non-vector sequential types

• CLJ-1363Field access via .- in reflective case does not work

• CLJ-944Compiler gives constant collections types which mismatch their runtime values