Changes to Clojure in Version 1.3 Beta

= CONTENTS =

1 Deprecated and Removed Features
1.1 Earmuffed Vars Are No Longer Automatically Considered Dynamic.
1.2 ISeq No Longer Inherits From Sequential
1.3 Disallow recur across try
1.4 Removed Bit Operation support for boxed numbers
1.5 Ancillary Namespaces No Longer Auto-Load on Startup:
2 New/Improved Features
2.1 Enhanced Primitive Support
2.2 Better Exception Reporting
2.3 clojure.reflect/reflect
2.4 clojure.data/diff
2.5 clojure.core/every-pred and clojure.core/some-fn Combinators
2.6 clojure.core/realized?
2.7 clojure.core/with-redefs-fn & with-redefs
2.8 clojure.core/find-keyword
2.9 clojure.repl/pst
2.10 clojure.pprint/print-table
2.11 pprint respects print-length
2.12 compilation and deployment via Maven
2.13 internal keyword map uses weak refs
2.14 ^:const defs
2.15 Message Bearing Assert
2.16 Error Checking for defmulti Options
2.17 Removed Checked Exceptions
2.18 vector-of Takes Multiple Arguments
2.19 deref with timeout
2.20 Walk Support for sorted-by Collections
2.21 string.join Enhanced to Work with Sets
2.22 clojure.test-helper
2.23 Newline outputs platform-specific newline sequence
2.24 init-proxy and update-proxy return proxy
2.25 doc & find-doc moved to REPL
2.26 clojure.java.shell/sh accepts as input anything that clojure.java.io/copy does
2.27 Interrupte Handler Promoted to clojure.repl
2.28 Add support for running -main namespaces from clojure.main
2.29 Set thread names on agent thread pools
2.30 Add docstring support to def
2.31 Comp function returns identity when called with zero arity
3 Performance Enhancements
4 Bug Fixes

= 1 Deprecated and Removed Features =

== 1.1 Earmuffed Vars Are No Longer Automatically Considered Dynamic. ==

(def fred)
=> Warning: fred not declared dynamic and thus is not dynamically rebindable, but its name suggests otherwise. Please either indicate ^:dynamic ** or change the name.

== 1.2 ISeq No Longer Inherits From Sequential ==

This allows anything that implements ISeq from being exclusively in the map or set equality partition.

== 1.3 Disallow recur across try ==

A compile-time exception is thrown if you attempt to recur across a try

(fn x (try (recur 1)))
=> CompilerException

== 1.4 Removed Bit Operation support for boxed numbers ==

Bit Operations map directly to primitive operations
Replicate has been deprecated in favor of repeat

== 1.5 Ancillary Namespaces No Longer Auto-Load on Startup ==

The following namespaces are no longer loaded on startup: clojure.set, clojure.xml, clojure.zip

= 2 New/Improved Features =

== 2.1 Enhanced Primitive Support ==

Full details here: http://dev.clojure.org/display/doc/Enhanced+Primitive+Support and http://dev.clojure.org/display/doc/Documentation+for+1.3+Numerics

== 2.2 Better Exception Reporting ==

Details here: http://dev.clojure.org/display/design/Error+Handling

Additionally:
Better error messages:

== 2.3 clojure.reflect/reflect ==

Full details here: http://dev.clojure.org/display/design/Reflection+API

== 2.4 clojure.data/diff ==

Recursively compares a and b, returning a tuple of things-only-in-a things-only-in-b things-in-both

(diff {:fred :ethel} {:fred :ethel})
=> fred :ethel}

== 2.5 clojure.core/every-pred and clojure.core/some-fn Combinators ==

every-pred takes a set of predicates and returns a function f that returns true if all of its composing predicates return a logical true value against all of its arguments, else it returns false.

((every-pred even?) 2 4 6)
=> true

((every-pred even?) 2 4 5)
=>false

some-fn takes a set of predicates and returns a function f that returns the first logical true value returned by one of its composing predicates against any of its arguments, else it returns logical false.

((some-fn even?) 2 4 5)
=> true
((some-fn odd?) 2 4 6)
=> false

== 2.6 clojure.core/realized? ==

Returns true if a value has been produced for a promise, delay, future or lazy sequence.

(let x (range 5)
(println (realized? x))
(first x)
(println (realized? x)))
=> false
=> true

== 2.7 clojure.core/with-redefs-fn & clojure.core/with-redefs ==

with-redefs-fn temporarily redefines Vars during a call to func. with-redefs temporarily redefines Vars while executing the body.

(with-redefs temp (println nil?))
=> :temp

== 2.8 clojure.core/find-keyword ==

Returns a Keyword with the given namespace and name if one already exists.

(find-keyword "def")
=> :def
(find-keyword "fred")
=> nil

== 2.9 clojure.repl/pst ==

Prints a stack trace of the exception

pst
=> (pst (IllegalArgumentException.))
IllegalArgumentException
user/eval27 (NO_SOURCE_FILE:18)
clojure.lang.Compiler.eval (Compiler.java:6355)
clojure.lang.Compiler.eval (Compiler.java:6322)
clojure.core/eval (core.clj:2699)
clojure.main/repl/read-eval-print--5906 (main.clj:244)
clojure.main/repl/fn--5911 (main.clj:265)
clojure.main/repl (main.clj:265)
clojure.main/repl-opt (main.clj:331)
clojure.main/main (main.clj:427)
clojure.lang.Var.invoke (Var.java:397)
clojure.lang.Var.applyTo (Var.java:518)
clojure.main.main (main.java:37)

== 2.10 clojure.pprint/print-table

Prints a collection of maps in a textual table.

(print-table fred :barney fred "ethel"} {:fred "wilma" :barney "betty"})
=> ===============
:fred | :barney
===============
ethel |
wilma | betty
===============

== 2.11 pprint respects print-length ==

Assigning print-length now effects output of pprint

== 2.12 compilation and deployment via Maven ==

See the following pages for more information http://dev.clojure.org/display/doc/Maven+Settings+and+Repositories http://dev.clojure.org/pages/viewpage.action?pageId=950842 http://dev.clojure.org/display/design/Common+Contrib+Build http://dev.clojure.org/display/design/How+to+Make+Releases

== 2.13 internal keyword map uses weak refs ==

== 2.14 ^:const defs ==

^:const lets you name primitive values with speedier reference.

(def constants
{:pi 3.14
:e 2.71})

(def ^:const pi (:pi constants))
(def ^:const e (:e constants))

The overhead of looking up :e and :pi in the map happens at compile time, as (:pi constants) and (:e constants) are evaluated when their parent def forms are evaluated.

== 2.15 Message Bearing Assert ==

Assert can take a second argument which will be printed when the assert fails

(assert (= 1 2) "1 is not equal to 2")
=> AssertionError Assert failed: 1 is not equal to 2

== 2.16 Error Checking for defmulti Options ==

defmulti will check to verify that its options are valid. For example, the following code will throw an example:

(defmulti fred :ethel :lucy :ricky)
=> IllegalArgumentException

== 2.17 Removed Checked Exceptions ==

Clojure does not throw checked exceptions

== 2.18 vector-of Takes Multiple Args ==

vector-of takes multiple args used to populate the array

(vector-of :int 1 2 3)
=> 1 2 3

== 2.19 deref with timeout ==

deref now takes a timeout option - when given with a blocking reference, will return the timeout-val if the timeout (in milliseconds) is reached before value is available.

(deref (promise) 10 :ethel)
=> :ethel

== 2.20 Walk Support for sorted-by Collections

Walk modified to work on sorted-by collections

let x (sorted-set-by > 1 2 3) (walk inc reverse x))
=> (2 3 4)

== 2.21 string.join Enhanced to Work with Sets ==

Just like join works on other collections

(join " and " #{:fred :ethel :lucy})
=> ":lucy and :fred and :ethel"

== 2.22 clojure.test-helper ==

All test helpers moved into clojure.test-helper

== 2.23 Newline outputs platform-specific newline sequence ==

Newline sequence is output as \r\n on Windows now.

== 2.24 init-proxy and update-proxy return proxy ==

Now you can chain calls on the proxy

== 2.25 doc & find-doc moved to REPL ==

Adds special form docs to the REPL

== 2.26 clojure.java.shell/sh accepts as input anything that clojure.java.io/copy does

This adds InputStream, Reader, File, byte[] to the list of inputs for clojure.java.shell/sh

== 2.27 Interrupte Handler Promoted to clojure.repl ==

Promoting this library eliminates the need for a dependency on old contrib.

== 2.28 Add support for running -main namespaces from clojure.main

This patch allows clojure.main to accept an argument pointing to a namespace to look for a -main function in. This allows users to write -main functions that will work the same whether the code is AOT-compiled for use in an executable jar or just run from source.

== 2.29 Set thread names on agent thread pools ==

It's a best practice to name the threads in an executor thread pool with a custom ThreadFactory so that the purpose of these threads is clear in thread dumps and other runtime operational tools.

Patch causes thread names like:

clojure-agent-send-pool-%d ��� should be fixed # of threads
clojure-agent-send-off-pool-%d ��� will be added and removed over time

== 2.30 Add docstring support to def ==

defs can now have docstrings

== 2.31 Comp function returns identity when called with zero arity ==

(= (comp) identity)
=> true

= 3 Performance Enhancements =

= 4 Bug Fixes =
The complete list of JIRA issues is here: http://dev.clojure.org/jira/secure/IssueNavigator.jspa?mode=hide&requestId=10052