Clojure JIRA

[CLJ-826] Include drop, take, butlast from clojure.contrib.string (1.2) in clojure.string 1.3

Fri, 2 Dec 2011 09:14:37 -0600

From clojure.contrib.string 1.2, I have found myself using drop, take,
and butlast. (These are more than just wrappers for String/substring,
because they behave nicely when indices exceed the string length.) I
like these methods in part because they match the behavior of
corresponding sequence methods, but have better performance. This
makes optimizing (when needed) easier.

[CLJ-821] should reify merge rather than replace on repeated specs?

Tue, 9 Aug 2011 14:18:40 -0500

reify, deftype, and the like fail silently if you specify a class twice:

(macroexpand '(reify Map (size [this] 0),
Counted (count [this] 0),
Map (keySet [this] nil)))
;=> (reify* [Counted Map] (count [this] 0) (keySet [this] nil))

The later Map section entirely supersedes the former, which I discovered when I wrote a macro that injects some automated method bodies into a reify for you.

I've attached a fix to make the above expand to the expected [for me, anyway] output.

[CLJ-806] clojure.test/are does not fail with insufficient arguments

Thu, 16 Feb 2012 11:43:13 -0600

If clojure.test/are is given an argument set with missing parameters, it silently ignores the extra parameters at the end instead of failing.

Clojure 1.3.0-master-SNAPSHOT
user=> (use 'clojure.test)
nil
user=> (deftest foo (are [x y] (= x y) 1 1 2 2 3 4))
#'user/foo
user=> (foo)

FAIL in (foo) (NO_SOURCE_FILE:6)
expected: (= 3 4)
  actual: (not (= 3 4))
nil
user=> (deftest missing-argument (are [x y] (= x y) 1 1 2 2 3))
#'user/missing-argument
user=> (missing-argument)
nil  ;; doesn't fail

[CLJ-785] Optimize /

Fri, 13 May 2011 09:26:14 -0500

Optimization to / such that the & more version expands to equivalent of (/ x (reduce * y more)) rather than (reduce / (/ x y) more). There should be an inlined variant of & more as well.

This was originally part of ~~CLJ-184~~, but was pulled out because it's big enough to be its own ticket. The rationale is that multiplies are significantly faster than divides on the JVM, and n-ary calls to / could be faster.

See "Java Multiplication (Much) Faster than Division" for background and Java benchmarks.

[CLJ-771] Move unchecked-prim casts to clojure.unchecked

Wed, 13 Feb 2013 00:51:11 -0600

Per Rich's comment in ~~CLJ-767~~:

Moving unchecked coercions into unchecked ns is ok

[CLJ-761] print-dup generates call to nonexistent method for APersistentVector$SubVector

Fri, 4 Nov 2011 11:31:09 -0500

Originally reported by Carson

print-dup on any collection type generates code to call the create method of the collection's class. APersistentVector$SubVector has no create method.

Example with Clojure at commit ecae8ff08a298777c365a261001adfe9bfa4d83c :

Clojure 1.3.0-master-SNAPSHOT
user=> (read-string (binding [*print-dup* true] (pr-str (subvec [1 2 3] 1))))
IllegalArgumentException No matching method found: create  clojure.lang.Reflector.invokeMatchingMethod (Reflector.java:50)

[CLJ-732] (keyword "") can be printed, but not read

Fri, 29 Jul 2011 07:49:21 -0500

user=> (keyword "")
:
user=> (prn-str *1)
":\n"
user=> (read-string *1)
java.lang.RuntimeException: java.lang.Exception: Invalid token: : (NO_SOURCE_FILE:0)

This obviously isn't a huge defect, but I'd argue that anything that can be printed should be readable.

[CLJ-720] check that argument to keys/vals is a Map

Fri, 28 Jan 2011 09:24:22 -0600

Current behavior:

If you call keys or vals on something that is not a Map, you do not get a ClassCastException until the KeySeq or ValSeq is consumed

Calling keys or vals on an empty collection of any type, even non-Map types, returns nil

The attached patch:

checks the type of the argument to keys and vals and throws IllegalArgumentException if it is neither java.util.Map nor null

changes tests for keys and vals to check that those functions throw IllegalArgumentException on empty collections that are not maps

[CLJ-698] class accessible from deftype method bodies is not suitable for instance?, ...

Wed, 29 Dec 2010 12:45:45 -0600

Example interaction: http://pastebin.com/cTdUCKfp
Which directly contradicts documentation for deftype

In the method bodies, the (unqualified) name can be used to name the class (for calls to new, instance? etc).

[CLJ-466] Reflection incorrectly avoids "More than one matching method" exceptions

Mon, 15 Nov 2010 12:49:00 -0600

From the google group:

The following correctly throws an IllegalArgumentException "More than one matching method" due to the nil resulting in ambiguity between two overloaded version of append.

(let [sb (StringBuilder.)]
  (.append sb nil))</code></pre>And yet the following, which uses reflection, works:
<pre><code>(def s nil)
(let [sb (StringBuilder.)]
  (.append sb s))

This is due to a divergence in method resolution between direct and reflected calls. Both examples should result in an exception due to ambiguity.

[CLJ-464] RFE: Run FindBugs on Clojure source code

Fri, 7 Oct 2011 07:33:23 -0500

I ran FindBugs (http://findbugs.sourceforge.net/ExampleName) on a small Clojure program that I am writing and got multiple warnings on code from the clojure libraries.

It might be helpful to run this on the source code base. It might uncover some actual bugs .

[CLJ-463] Strip leading colons when creating keywords from single strings

Fri, 19 Nov 2010 10:07:07 -0600

This seems unfortunate:

=> (-> :foo str keyword)
::foo

Symbols are far saner in this regard:

=> (-> 'foo str symbol)
foo

Simply stripping leading colons from strings prior to turning them into keywords should suffice. The 2-arity Keyword.intern method and clojure.core/keyword fn should be left intact, so as to provide an escape hatch for those that really do need colon-prefixed keywords.

[CLJ-461] require namespace implicitly

Tue, 21 Jun 2011 18:41:38 -0500

Referencing a function with a fully-qualified namespace should work without first using require or use, similar to how a fully-qualified java class can be used without importing it.

It's a small change in Compiler that tries to call (require x) if the fully qualified classname is not found. This should give priority to the java class, which protects backwards compatibility. There is no runtime performance impact, only compile time (the first time the namespace is seen). The fact that code (the namespace) is loaded during compilation of a form is no different than loading code to look up a java class.

This makes it easier to write quick scripts as in the example below, also to use one-liners in the repl or ad hoc in code.

For example: java -cp src/clj/:classes clojure.main -e "(clojure.set/union #{1} #{2})"

Currently on master, this produces: Exception in thread "main" java.lang.ClassNotFoundException: clojure.set
but this works: java -cp src/clj/:classes clojure.main -e "(require 'clojure.set) (clojure.set/union #{1} #{2})"

Obviously, (use) would make the code shorter, but my goal is to make it implicit.

Discussion: http://groups.google.com/group/clojure-dev/t/69823ce63dd94a0c

[CLJ-459] RFE: modify description of "assoc"

Thu, 14 Oct 2010 16:55:00 -0500

The documentation for "assoc" in clojure.core should probably
include

(assoc vector index val)
</code></pre>
and

<pre><code>(assoc vector index val & ivs)

in the usage line.

[CLJ-455] Calculating large numbers results in java.math.BigIntegerArithmeticException

Sat, 23 Oct 2010 22:52:00 -0500

(class (* 1000 1000 1000 1000 1000 1000 1000))
1.1 returns : java.math.BigInteger
1.3.0-alpha returns : java.math.BigIntegerArithmeticException integer overflow clojure.lang.Numbers.throwIntOverflow (Numbers.java:1575)

[CLJ-451] fn literals lack name/arglists/namespace metadata

Tue, 5 Oct 2010 00:29:00 -0500

I would expect (meta (fn not-so-anonymous [a b c])) to include {:name not-so-anonymous :arglists ([a b c])} alongside line number information and possibly namespace/file as well, but currently it only includes :line.

[CLJ-450] Add default predicate argument to filter, every?, take-while

Fri, 27 Apr 2012 11:38:28 -0500

Some seq processing functions that take predicates could be improved by the addition of a default value of identity for the predicate argument.

This has been discussed on the mailing list, and people seem favorable:
http://groups.google.com/group/clojure/browse_thread/thread/600559b7ee261908/3bc5d144ac54854e?lnk=gst&q=filter+identity#3bc5d144ac54854e
http://groups.google.com/group/clojure-dev/browse_thread/thread/0a9b5750dd7ec4ca

I can put together a patch.

[CLJ-449] NullPointerException in clojure.stacktrace

Fri, 5 Nov 2010 11:05:12 -0500

See http://groups.google.com/group/clojure-dev/browse_thread/thread/f4157c68df730bd9

clojure.stacktrace/print-trace-element tries to match StackTraceElement.getClass against a regex.
StackTraceElement.getClass returns null, so a NullPointerException gets thrown, totally obscuring the original exception.

Now, the null is supposedly impossible, according to the Javadocs for StackTraceElement. But in some rare cases it seems to happen.

[CLJ-446] 1.3 alpha1 gives reflection warning in a case where 1.2 does not

Fri, 9 Dec 2011 15:20:10 -0600

Feel free to reclassify this as something other than a bug if I've misclassified it.

Related Clojure Google group conversation: http://groups.google.com/group/clojure/browse_thread/thread/83c08f6c2f313c50#

When doing AOT compilation on the attached program nbody.clj with 1.2:

java -Dclojure.compile.path=. -cp clojure-1.2.0.jar:. clojure.lang.Compile nbody

there are no reflection warnings, and a more complex version of the program using the type Body runs quickly. When doing AOT compilation with 1.3 alpha1:

java -Dclojure.compile.path=. -cp clojure-1.3.0-alpha1.jar:. clojure.lang.Compile nbody

I see these reflection warnings, and a more complex version of the program using the type Body runs significantly more slowly, most likely due to the reflection warned about:

Reflection warning, nbody.clj:18 - reference to field x can't be resolved.
Reflection warning, nbody.clj:19 - reference to field y can't be resolved.

Changing the name of the file to nbod.clj and the first line to "(ns nbod", and making corresponding changes to the compilation commands above, causes the reflection warnings to go away in 1.3 alpha1.

Similarly, taking the original attached file nbody.clj and replacing the three occurrences of "nbody" that are not the namespace name with a different name like "nbod" (or probably any name other than "nbody") also causes the reflection warnings to go away in 1.3 alpha1.

In case it makes any difference, I was using Clojure jars pulled via Leiningen, and HotSpot 1.6.0_xxx JVMs on Mac OS X 10.5.8 and Ubuntu 10.4.

Admittedly, a change with very limited impact on typical Clojure users. I wanted to file a ticket in case this was an unwanted consequence of some desirable change in 1.3.

[CLJ-440] java method calls cannot omit varargs

Mon, 29 Oct 2012 10:56:32 -0500

From http://groups.google.com/group/clojure/browse_thread/thread/7d0d6cb32656a621

E.g., trying to call java.util.Collections.addAll(Collection c, T... elements)

user=> (Collections/addAll [] (object-array 0))
false
user=> (Collections/addAll [])
IllegalArgumentException No matching method: addAll  clojure.lang.Compiler$StaticMethodExpr.<init> (Compiler.java:1401)

The Method class provides an isVarArg() method, which could be used to inform the compiler to process things differently.

[CLJ-438] case* and code walkers

Fri, 13 Apr 2012 08:03:18 -0500

Clojure 1.2.0-master-SNAPSHOT
user=> (use 'clojure.walk)
nil
user=> (eval (macroexpand-all '(case 1 1 :test)))
java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to clojure.lang.MapEntry (NO_SOURCE_FILE:2)

user=> (macroexpand-all '(case 1 1 :test))
(let* [G__9 1]
(case* G__9 0 1 1 1
(throw (new java.lang.IllegalArgumentException (clojure.core/str "No matching clause: " G__9)))

{1 [1 :test]}

false))

The existing code walkers convert the embedded [1 :test] into a PersistentVector that the compiler doesn't accept.
(symbol-macrolet [x :test] (case 1 1 x)) fails in the same way.

[CLJ-436] Bug in clojure.contrib.json/read-json

Fri, 1 Oct 2010 15:32:00 -0500

What (small set of) steps will reproduce the problem?
$ java -cp lib/clojure-1.2.0.jar:lib/clojure-contrib-1.2.0.jar clojure.main
Clojure 1.2.0
user=> (require 'clojure.contrib.json)
nil
user=> (clojure.contrib.json/read-json "")
java.lang.IllegalArgumentException: Value out of range for char: -1 (NO_SOURCE_FILE:0)
user=>

What is the expected output? What do you see instead?

Expected:

(if eof-error?
  (throw (EOFException. "JSON error (end-of-file)"))
  eof-value)

What version are you using?
1.2

Was this discussed on the group? If so, please provide a link to the discussion
[13:51] <na_ka_na> Hey guys I think there's a bug in clojure.contrib.json at line 116
[13:51] <na_ka_na> in clojure 1.2
[13:52] <na_ka_na> it has a (char i) and then checks for (= i -1) ... but (char -1) fails
[13:52] <na_ka_na> where can I report it ?
[13:53] <LauJensen> na_ka_na: assembla/support

[CLJ-434] Additional copy methods for URLs in clojure.java.io

Fri, 10 Sep 2010 07:32:00 -0500

The copy method in clojure.java.io doesn't handle java.net.URL as input.
The necessary methods can be found in the mailing list post:
[[url:http://groups.google.com/group/clojure/browse_thread/thread/24a105b12466a8e8]]

[CLJ-431] with-junit-output should use with-test-out when writing header and testsuites tags

Fri, 5 Nov 2010 11:05:12 -0500

Need to be able to use *test-out* and *out* independently within with-junit-output in order to be able to XML escape general test output while leaving report output (XML) alone.

with-junit-output currently precludes this because it doesn't use with-test-out when writing the header and testsuites tags. It assumes it will always be wrapped with with-test-out but this permenantly merges *test-out* and *out*

[CLJ-424] instance? fails on deftype instance, when used from multiple files

Fri, 28 Jan 2011 15:43:25 -0600

When instance? is called from two separate namespaces to test an instance of a user defined type, one of them fails

In the attached project, the following (identical) tests run correctly:

lein test instance-test.test.core
lein test instance-test.test.core2

but this fails:

lein test

For ease of reference, the attached project contains the following:

(ns instance-test.core)
(deftype MyType [a])
(defn make-my-type
[]
(MyType. nil))

(ns instance-test.test.core
(:use [instance-test.core] :reload-all)
(:use [clojure.test])
(:import instance-test.core.MyType))

(deftest test1
(is (instance? instance-test.core.MyType (make-my-type))))

(ns instance-test.test.core2
(:use [instance-test.core] :reload-all)
(:use [clojure.test])
(:import instance-test.core.MyType))

(deftest test1
(is (instance? instance-test.core.MyType (make-my-type))))

[CLJ-419] LispReader uses Character.isWhitespace rather than Character.isSpaceChar

Sat, 23 Oct 2010 15:03:00 -0500

Character.isWhitespace doesn't handle non-breaking space correctly. Apparently it's pretty ancient from The Olden Days Before People Knew How To Do Character Encodings.

In Java 1.5 Character.isSpaceChar was added, which handles supplementary characters the right way: http://download.oracle.com/javase/1.5.0/docs/api/java/lang/Character.html#isWhitespace(char)

[CLJ-416] improvments on agent

Fri, 1 Mar 2013 12:47:03 -0600

hi,i have some ideas to improve the agent system:
1.Agent's thread pool must use a custom ThreadFactory to new threads.Set new thread a system name and set it to be daemon.Thread's name would be used for debug or monitor.And set thread to be daemon asking user to shutdown agents explicitly.

2.Beacause agent's thread is daemon,so if a application doesn't use any agents,the thread pool must not started.I think the agent's thread pools should be lazy initialized.

3.I think agent must allow use to define a agent-own thread pool.That thread pool is only used by a agent,not global.just like:
(define a (agent :executor (java.util.concurrent.Executors/newFixedThreadPool 2)))
or
(set-executor! a (java.util.concurrent.Executors/newFixedThreadPool 2))
And then,a new function to shutdown agent's custom thread pool:
(shutdown-agent a)

Why do we need a custom thread pool?
First, the default thread pool is global, send use the thread pool
is a fixed size cpus +2, is likely to become the system bottleneck
sometime. Although you can use the send-off, use the cache thread
pool, but in a real world application, I can not use the cache thread
pool, which will introduce the risk of OutOfMemoryError, normally I
like to use a fixed-size thread pool.

Second, the actions which global thread pool execute are from a
variety of agents, the actions are not homogeneous, and can not
maximize the efficient use of the thread pool.

These are my suggestions on agent,thanks for this great language,i enjoy it.

[CLJ-414] In latest clojure, empty list is neither true nor false

Tue, 24 Aug 2010 00:35:00 -0500

In latest Clojure, compiled today:

user> (true? ())
false
user> (false? ())
false

This makes empty collections the only entities in Clojure which are neither true, nor false.
I'm fairly sure () used to be true – is this an intentional change? Googling reveals lots of warnings about the empty list not being false in Clojure.

[CLJ-412] clojure.xml/emit, emit-element are not documented at clojure.org

Tue, 24 Aug 2010 00:34:00 -0500

Neither function makes an appearance here:
http://clojure.github.com/clojure/clojure.xml-api.html
Despite the fact that neither appears to be private. Perhaps the doc generator just ignores all functions that have no doc comment?

[CLJ-411] clojure.xml/emit should be encoding-aware

Fri, 1 Oct 2010 09:56:00 -0500

clojure.xml/emit blithely asserts that it's writing UTF-8 despite the fact that it's actually writing characters, not bytes. Encoding isn't actually decided until actual bytes are written. This forces clients using clojure.xml/emit to write XML back to disk to use UTF-8. They won't know to do that unless they actually peek at the implementation. This behavior isn't documented.

(defn emit [x]
  (println "<?xml version='1.0' encoding='UTF-8'?>")
  (emit-element x))

[CLJ-409] SAXParserFactoryImpl is missing at unit testing time

Tue, 24 Aug 2010 00:34:00 -0500

SAXParserFactoryImpl seems to be AWOL while clojure unit tests are running, but is present when clojure is started from the command line. WTF?

(ns clojure.test-clojure.clojure-xml
  (:use clojure.test)
  (:import [javax.xml.parsers SAXParserFactory])
  (:require [clojure.xml :as xml]))

(deftest sax-parser-factory-is-not-awol
  (is (SAXParserFactory/newInstance)))
</code></pre>
<pre><code>Tell ant to run the unit tests:

$ ant test

And get the following exception:

ERROR in (sax-parser-factory-is-not-awol) (SAXParserFactory.java:134)
expected: (SAXParserFactory/newInstance)
actual: javax.xml.parsers.FactoryConfigurationError: Provider
        org.apache.xerces.jaxp.SAXParserFactoryImpl not found
at javax.xml.parsers.SAXParserFactory.newInstance (SAXParserFactory.java:134)
   clojure.test_clojure.clojure_xml/fn (clojure_xml.clj:17)

Yet, when I run clojure from the command line and do the same thing,
all is well.

$ java -jar clojure.jar
Clojure 1.2.0-beta1
user=> (import 'javax.xml.parsers.SAXParserFactory)
javax.xml.parsers.SAXParserFactory
user=> (SAXParserFactory/newInstance)
#<SAXParserFactoryImpl org.apache.xerces.jaxp.SAXParserFactoryImpl@19381960>
user=>

[CLJ-408] clojure.xml emit does not properly escape attribute and element content

Mon, 15 Nov 2010 12:49:00 -0600

(with-out-str
  (clojure.xml/emit-element {:tag :e :attrs nil :content "&"}))
</code></pre>
produces: <e>&</e>
correct would be: <e>&amp;</e>
This is true for both element content and attribute content. < and > are not escaped as well. Furthermore, apostrophe ( ' ) in an attribute value leads to broken xml:
<pre><code>
<e a='''/>

[CLJ-406] Typo in underive causes breaking in the resulting hierarchy

Tue, 24 Aug 2010 18:31:00 -0500

There's a typo on line 4515 in core.clj, in the definition of underive:

{:parent ... }
; should be
{:parents ... }
</code></pre>
causing breakage in hierarchies which had relationships underived in them.

E.g.
<pre><code>
(derive ::foo ::bar)
(underive ::foo ::bar)
(derive ::foo ::bar)
; => NPE

#clojure discussion:

http://clojure-log.n01se.net/date/2010-07-21.html#20:54

[CLJ-405] better error messages for bad defrecord calls

Tue, 24 Aug 2010 00:28:00 -0500

defrecord could tell you if, e.g., you didn't specify an interface before leaping into method bodies. See http://groups.google.com/group/clojure/browse_thread/thread/f52f90954edd8b09

[CLJ-401] Promote "seqable?" from contrib?

Tue, 24 Aug 2010 09:19:00 -0500

This was vaguely discussed here and could potenntially help this ticket as well as be generally useful.

I don't speak for everyone but when I saw sequential? I assumed it would have the semantics that seqable? does. Just my opinion, I'd love to hear someone's who is more informed than mine.

In the proposed patch referenced in the ticket above, if seqable? could be used in place of sequential? flatten could be more powerful and work with maps/sets/java collections. Here's how it would look:

(defn flatten [coll]
  (lazy-seq
    (when-let [coll (seq coll)]
      (let [x (first coll)]
        (if (seqable? x)
          (concat (flatten x) (flatten (next coll)))
          (cons x (flatten (next coll))))))))

And an example:

user=> (flatten #{1 2 3 #{4 5 {6 {7 8 9 10 #�tok1-block-tok}}}})
(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18)

[CLJ-400] A faster flatten

Tue, 24 Aug 2010 00:19:00 -0500

As discussed in this thread, I am submitting a more performant version of flatten for review. It has the same semantics as the current core/flatten. I have also updated the doc string to say that "(flatten nil) returns the empty list", because that's what the current version of core/flatten does as well.

I haven't mailed in a CA yet, but I will tomorrow morning.

Edit: Of course I'd mess my first ticket up . I am not immediately seeing an option to edit this to add the "patch" tag or add the "ready to test" action. Sorry folks

[CLJ-396] Better support for multiple inheritance in hierarchies and multimethods

Tue, 24 Aug 2010 11:06:00 -0500

While the hierarchies produced with 'derive' allow multiple parents per child, there is no way to indicate precedence between those parents, other than by laboriously specifying 'prefer-method' for every type X every multimethod. When 2 multimethods are both applicable to the supplied arguments, Clojure produces a nonspecific IllegalArgumentException containing only an error string. All this means that while Clojure does have an "inheritance" mechanism in the form of the ad hoc hierarchies, it is currently not really possible to implement multiple inheritance using the ad hoc hierarchy mechanism. 'Prefer-method' will not scale up to use in large applications with complex type hierarchies and heavy use of multimethods.

Some potential ways to solve this are:

allowing 'defmulti' to take a 'tie-breaker' function (tie-breaker [arglist speclist1 speclist2] ...) which is called instead of throwing an IllegalArgumentException, and must return the 'winning speclist'.
instead of throwing IllegalArgumentException, throw a TiedMultiMethodsException – the exception instance should contain the offending speclists, the function, and the arguments that were supplied.
allowing specification of precedence when using 'derive' (if only via a "last in = highest precedence" rule).

Paul

[CLJ-395] "underive" corrupts ad hoc hierarchies.

Tue, 24 Aug 2010 11:06:00 -0500

See transcript below, from 1.20-dev snapshot compiled about a week ago:

user=> (derive ::dad ::grandad)
nil
user=> (derive ::son ::dad)
nil
user=> (underive ::dad ::grandad)
nil
user=> (derive ::dad ::grandad)
java.lang.NullPointerException (NO_SOURCE_FILE:0)
user=> (derive ::foo ::bar)
java.lang.NullPointerException (NO_SOURCE_FILE:0)
user=>

[CLJ-379] problem with classloader when run as windows service

Tue, 24 Aug 2010 10:40:00 -0500

I found following error when I run clojure application as MS Windows service (via procrun from Apache Daemon project). When I tried to do 'require' during run-time, I got NullPointerException. This happened as baseLoader function from RT class returned null in such environment (the value of Thread.currentThread().getContextClassLoader()). (Although my app works fine when I run my application as standalone program, not as service).
This error was fixed by explicit setting of class loader with following code:

(.setContextClassLoader (Thread/currentThread) (java.lang.ClassLoader/getSystemClassLoader))

before any call to 'require'....

May be you need to modify 'baseLoader' function, so it will check is value of Thread.currentThread().getContextClassLoader() is null or not, and if null, then return value of java.lang.ClassLoader.getSystemClassLoader() ?

[CLJ-375] metadata literal enhancements

Tue, 28 Sep 2010 15:51:00 -0500

1) Merge metadata literals (i.e. metadata on literal with metadata adds to it rather than replaces (but will replace same key))
^{:fred :ethel} ^{:ricky :lucy} foo yields metadata of {:fred :ethel, :ricky :lucy}

2) ^:a-keyword becomes {:a-keyword true} metadata

[CLJ-363] defn doesn't put the right metadata on its fn value

Tue, 24 Aug 2010 08:20:00 -0500

duplicate of #270

user=> (defn foo {:bar :baz} [] 42)
#'user/foo
user=> (meta #'foo)
{:ns #<Namespace user>, :name foo, :file "NO_SOURCE_PATH", :line 221, :arglists ([]), :bar :baz}
user=> (meta foo)
{:ns #<Namespace user>, :name foo} ; the value has only the basic keys
user=> (defn foo {:lucy :ethel} [] 43)
#'user/foo
user=> (meta #'foo)
{:ns #<Namespace user>, :name foo, :file "NO_SOURCE_PATH", :line 224, :arglists ([]), :lucy :ethel}
user=> (meta foo) ; the value has the previous metadata
{:ns #<Namespace user>, :name foo, :file "NO_SOURCE_PATH", :line 221, :arglists ([]), :bar :baz}

[CLJ-354] <= and >= comparisons against NaN return true

Sat, 19 Mar 2011 18:44:55 -0500

I would expect the attached clojure program to have the same output as the attached java program. However, their output differs. The following is a unidiff from the clojure output to the java output, i.e., each line beginning with a minus sign is what I would consider wrong output, and the corresponding line beginning with a plus sign is the correct output.

@@ -14,3 +14,3 @@

<= 0 NaN true
<= NaN 1 true
<= NaN NaN true
+ <= 0 NaN false
+ <= NaN 1 false
+ <= NaN NaN false
@@ -22,3 +22,3 @@
>= 0 NaN true
>= NaN 1 true
>= NaN NaN true
+ >= 0 NaN false
+ >= NaN 1 false
+ >= NaN NaN false

Here Java follows IEEE 754; see also <http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#153654>.

I suspect the bug is because clojure.lang.Numbers.lte(x,y) is implemented by negating the result of lt(y,x), and similarly for gte: <http://github.com/richhickey/clojure/blob/65ae4928119a50e892bc33e8cbb47a82ebef98ee/src/jvm/clojure/lang/Numbers.java#L193>.

This is with Clojure 1.2.0-master-SNAPSHOT (git hash 65ae4928119a50e892bc33e8cbb47a82ebef98ee).

I mentioned this on the Google group, but no-one commented anything: <http://groups.google.com/group/clojure/browse_thread/thread/623d7f50fafaa816>.

[CLJ-350] namespace function NPE if namespace does not exist

Fri, 1 Oct 2010 16:45:00 -0500

The namespace function throws an NPE if the namespace of the symbol does not exist. For example:

(namespace ::x/y)
;=> NPE

The following patch changes corrects this. The resulting code throws an IllegalArgumentException with the message: "Namespace does not exist: x".

(Note: My Contributor's Agreement is in place, but since my request to join the Google clojure-dev group is still pending I decided to go ahead and submit the patch here.)

-David McNeil

====

From 5d65e5d9aabebf4ea5961e4e0bd8483618f8247e Mon Sep 17 00:00:00 2001
From: David McNeil <dem@dem-laptop.(none)>
Date: Sat, 15 May 2010 10:55:28 -0500
Subject: [PATCH] Avoid NPE and throw better exception if symbol's namespace does not exist.

—
src/jvm/clojure/lang/LispReader.java | 6 ++++--
1 files changed, 4 insertions, 2 deletions

diff --git a/src/jvm/clojure/lang/LispReader.java b/src/jvm/clojure/lang/LispReader.java
index 0bfae97..361b9cc 100644
— a/src/jvm/clojure/lang/LispReader.java
+++ b/src/jvm/clojure/lang/LispReader.java
@@ -302,9 +302,11 @@ private static Object matchSymbol(String s){
{
Symbol ks = Symbol.intern(s.substring(2));
Namespace kns;

if(ks.ns != null)
+ if(ks.ns != null) { kns = Compiler.namespaceFor(ks); - else + if(kns == null) + throw new IllegalArgumentException("Namespace does not exist: " + ks.ns); + } else
kns = Compiler.currentNS();
//auto-resolving keyword
return Keyword.intern(kns.name.name,ks.name);
- 1.6.3.3

[CLJ-346] (pprint-newline :fill) is not handled correctly

Mon, 29 Nov 2010 20:48:05 -0600

Filled pretty printing (where we try to fit as many elements on a line as possible) is being too aggressive as we can see when we try to print the following array:

user> (binding [*print-right-margin* 20] (pprint (int-array (range 10))))

Produces:

[0,
1,
2,
3,
4, 5, 6, 7, 8, 9]

Rather than

[0, 1, 2, 3, 4,
5, 6, 7, 8, 9]

or something like that. (I haven't worked through the exact correct representation for this case).

We currently only use :fill style newlines for native java arrays.

[CLJ-345] clojure.contrib.string.replace-str throws NPE on nil string

Fri, 1 Oct 2010 06:44:00 -0500

Version: Clojure 1.2 / clojure-contrib 1.2

This call:

user=> (clojure.contrib.string/replace-str "a" "b" nil)
#<CompilerException java.lang.NullPointerException (NO_SOURCE_FILE:29)>

throws a NullPointerException when passed a nil string. It seems like more corner cases could be automatically handled by returning nil in this case rather than throwing an NPE. At the very least, it would be nice to update the docstring to state that s cannot be nil.

[CLJ-339] Integer autopromotion error

Fri, 1 Oct 2010 10:13:00 -0500

From this thread:
http://groups.google.com/group/clojure/browse_thread/thread/db1ffbb36c7d6f48

user=>(def imax (Integer/MAX_VALUE))
user=>(+ imax imax)
4294967294

user=>(+ (Integer/MAX_VALUE) (Integer/MAX_VALUE))
java.lang.ArithmeticException: integer overflow (NO_SOURCE_FILE:0)

Also:
user=>(+ Integer/MAX_VALUE Integer/MAX_VALUE)
java.lang.ArithmeticException: integer overflow (NO_SOURCE_FILE:0)

user=> (+ (Integer/MAX_VALUE) imax)
4294967294

user=> (+ imax (Integer/MAX_VALUE))
4294967294

user=> (+ Integer/MAX_VALUE Integer/MAX_VALUE Integer/MAX_VALUE)
6442450941

Possibly a bug with inlining?

[CLJ-319] TransactionalHashMap bug

Fri, 1 Oct 2010 16:06:00 -0500

TransactionalHashMap computation of the bin is buggy. The implementation doesn't unset the sign bit before using it in accessing the bin array which in some cases cause an ArrayOutOfBoundException to be thrown.

As Rich Hickey has pointed out, this is an unsupported experimental Class and won't be fixed unless I provided a patch, so attached is the patch file.

[CLJ-308] protocol-ize with-open

Fri, 13 Apr 2012 12:52:37 -0500

Good use (and documentation example) of protocols: make with-open aware of a Closable protocol for APIs that use a different close convention. See http://groups.google.com/group/clojure/browse_thread/thread/86c87e1fc4b1347c

[CLJ-304] contrib get-source no longer works with deftype

Fri, 3 Dec 2010 11:44:01 -0600

Now that deftype creates a class (but not a var), you can't use c.c.repl-utils/get-source on a deftype. Is there something we can do on the Clojure side to help this work again?

[CLJ-293] doto doc minor typo

Tue, 24 Aug 2010 16:23:00 -0500

doto doc has a small typo

[CLJ-288] Make clojure.core/merge-with accept a wider range of map types

Fri, 24 Aug 2012 07:40:43 -0500

The current implementation of merge-with works only with map types that implement the IFn protocol for key lookup. In particular, this means that it doesn't work with map-like types created with deftype. The attached patch replaces the call to the map by a call to clojure.core/get, which works on any map-like type.

[CLJ-287] (take-nth 0 coll) spins wheels on Solaris

Tue, 24 Aug 2010 10:10:00 -0500

(take-nth 0 (range 5)) is a silly thing to do, but if you're anything like me then it inexorably fills heap space and cpu time by an infinite number of RMI calls.
I'm running Clojure 1.1.0-master-SNAPSHOT under Java 1.6R17 on Solaris 10 and I watched it fill up to 56GB
I think it should raise an exception instead but Im too new to clojure to recommend one. Sorry
Cheers
Simon

[CLJ-284] Cannot cast 0xFF to a byte (fails range check)

Tue, 28 Sep 2010 13:05:00 -0500

Prompted by a thread on the clojure group.

The recently added range checking to casts/coercions adversely affects a common usage of the byte cast to pull the 8 LSBs of an integer. Since the numerical representation of a byte is signed in java, the Byte.MIN_VALUE</code> and <code>Byte.MAX_VALUE</code> used in the range check of <code>clojure.lang.RT.byteCast() do not allow for integer values up to 0xFF.

[CLJ-283] recur ignores rest args

Tue, 24 Aug 2010 07:55:00 -0500

When you recur inside a function, the arguments are not assigned as expected:

(defn weird [& b]
(println b)
(when (< (first b) 2)
(recur (inc (first b)))))

(weird 1)

The first time it runs, b is a seq, but the second time it's just an integer.

After some discussion I found out this is because there's no way to apply recur, so technically making recur act as a normal function call means you can't pass a seq of args in. While this is arguably a decent workaround, it leads to very confusing, undocumented behaviour; at the very least it should be tracked in an issue until a better solution can be found.

[CLJ-279] Numbers as keys in maps must be of the same class to match

Tue, 28 Sep 2010 09:23:00 -0500

In maps, numbers need to be of the same class to match:

({(BigInteger. "1") "one"} 1) => nil
({(Long. "1") "one"} 1) => nil
({(Integer. "1") "one"} 1) => "one"

although:

(= (BigInteger. "1") 1) => true
(= (Long. "1") 1) => true

[CLJ-277] Making clojure.xml/emit a little friendler to xml consumers

Tue, 24 Aug 2010 09:41:00 -0500

Currently, clojure.xml/emit breaks the eBay api, because emit adds whitespace before and after :contents. This trivial patch fixes it for me:
http://github.com/tjg/clojure/commit/bbff079d26e627c655b847319a58d76b8b3cec7c

(Dunno whether there's a good reason emit works that way, or if I'm missing something obvious.)

I realize that emit's behavior conforms to the XML spec and it's probably eBay at fault here. But I can nevertheless see this whitespace causing problems.

[CLJ-274] cannot close over mutable fields (in deftype)

Fri, 1 Oct 2010 09:35:00 -0500

Simplest case:

user=>
(deftype Bench [#^{:unsynchronized-mutable true} val]
Runnable
(run [_]
(fn [] (set! val 5))))

java.lang.IllegalArgumentException: Cannot assign to non-mutable: val (NO_SOURCE_FILE:5)

Functions should be able to mutate mutable fields in their surrounding deftype (just like inner classes do in Java).

Filed as bug, because the loop special form expands into a fn form sometimes:

user=>
(deftype Bench [#^{:unsynchronized-mutable true} val]
Runnable
(run [_]
(let [x (loop [] (set! val 5))])))
java.lang.IllegalArgumentException: Cannot assign to non-mutable: val (NO_SOURCE_FILE:9)

[CLJ-273] def with a function value returns meta {:macro false}, but def itself doesn't have meta

Tue, 24 Aug 2010 09:32:00 -0500

On the master (1.2) branch, if you create a def with an initial function value, {:macro false} is added to the metadata of the return value for def. However, if you look again at the metadata on the var itself, the {:macro false} is not present! This breaks the use of contrib's defalias when aliasing macros, because the new alias is marked as {:macro false}.

The code below demonstrates the issue, which was introduced in http://github.com/richhickey/clojure/commit/430dd4fa711d0008137d7a82d4b4cd27b6e2d6d1, "metadata for fns."

;; all running on 1.2, DIFF noted in comments

(defmacro foo [])
-> #'user/foo

(meta (def bar (.getRoot #'foo)))
-> {:macro false, :ns #<Namespace user>, :name bar, :file "NO_SOURCE_PATH", :line 83}
;; DIFF: where did that :macro false come from??

(def bar (.getRoot #'foo))
-> #'user/bar

(meta #'bar)
-> {:ns #<Namespace user>, :name bar, :file "NO_SOURCE_PATH", :line 84}
;; LIKE 1.1, but really weird: now the :macro false is gone again!

[CLJ-272] load/ns/require/use overhaul

Tue, 28 Feb 2012 03:56:11 -0600

Creating this ticket to describe various things people have wanted to change about how ns works:

Minimal needs

there should be a primitive level of loading (presumably load) that just loads without question.
the api should be unified across the ns and direct forms. No more keywords or quoting! So (use foo)</code> not <code>(use 'foo)</code>. This makes <code>use</code> et al macros, so there should also be new fn versions (maybe <code>use*).

Other possibilities to discuss.

Feature addressing the {{:like</code> and <code>:clone</code> ideas from http://onclojure.com/2010/02/17/managing-namespaces/. I think I would prefer a single new option <code>:clone</code> which allows <code>:only</code> and <code>:exclude}} features as subspecifiers.
Convenience fn to unmap all names in a namespace?

[CLJ-255] add denominator and numerator fns for Ratio

Tue, 28 Sep 2010 07:07:00 -0500

currently the only way to get the denominator or numerator is via the exposed fields of the Ratio class.

On Thu, Jan 21, 2010 at 7:57 AM, Jacek Generowicz
<jacek.generowicz@googlemail.com> wrote:
> Clojure has a Ratio type; presumably there should be an easy way to
> find the numerator and denominator of a Ratio object.
>
> I didn't have much luck on clojure.org or with find-doc, but
>
> (show 1/2)
>
> taught me that there are numerator and denominator methods on Ratio's
> underlying Java implementation, so I can now do:
>
> (.numerator 1/2) ; => 1
> (.denominator 1/2) ; => 2
>
> Is there a more direct way? (Not that this is bad! But you can't
> use .numerator as a first-order function (though #(.numerator %) is
> still pretty damn good).)
>
> In general, do you have any hints on how to go about looking for
> useful Clojure functions which work with certain Clojure types ?
>

[CLJ-251] macroexpand should respect :inline

Fri, 7 Oct 2011 07:47:38 -0500

macroexpand and macroexpand-1 currently do not respect the :inline metadata of
functions. For example you currently see:

(macroexpand '(+ 1 2))
;=> (+ 1 2)

Instead, macroexpand should return something like:

;=> (. clojure.lang.Numbers (add 1 2))

...depending of course on the exact definition of +'s :inline fn.

[CLJ-238] Make re-pattern accept multiple arguments to concatenate them.

Fri, 7 Oct 2011 07:51:41 -0500

This would help concatenating multiple regular expressions. The attached patch simply converts all arguments to a string and then pass that string to re-pattern. Currently if you're trying to concatenate literal regular expressions, you're force to use the str function. It's not much extra code, but given the similarity between re-pattern and str, I thought it would be nice to have them behave the same way. e.g.:

(re-pattern (apply str (map (partial format "%s{%s}") [\a \b \c \d \e] (iterate inc 1))))
would become
(apply re-pattern (map (partial format "%s{%s}") [\a \b \c \d \e] (iterate inc 1)))

It only save one call to str, so it might not warrant the extra code in the end.

[CLJ-237] Adding a :only-keys destructuring option, that throws an exception if there's extra key(s).

Fri, 17 Feb 2012 14:15:44 -0600

While discussing the issue that prompted ticket [[ticket:236]] on clojure-dev, Richard Newman suggested modifying map destructuring to incorporate a :only-keys. It works exactly like :keys but raises an exception if the destructured map contains other keys. The attached patch shows a possible implementation.

[CLJ-233] better error reporting of nonexistent var

Wed, 29 Sep 2010 05:29:00 -0500

simple improvement to error message when referencing a var that doesn't exist.

[CLJ-213] Invariants and the STM

Tue, 24 Aug 2010 07:23:00 -0500

(ticket requested here http://groups.google.com/group/clojure/browse_thread/thread/119311e89fa46806/4903ce25ff6deaa6#4903ce25ff6deaa6)

The general idea is to declare invariants inside a transaction and, when at commit time an invariant doesn't hold anymore, the transaction retries.
So it can both act as a kind of soft ensure or to specify actions that "partially commute".
Thus it would enable coarser refs.

See the attached file for quick prototype.

User code would looks like:

(invariant (@world :key))
(commute world update-in [:key] val-transform-fn)

This means the commute will occur only if (@world :key) returns the same value in-transaction and at commit point.

[CLJ-212] Direct linking breaks clojure.contrib.repl-ln.

Tue, 24 Aug 2010 05:22:00 -0500

Direct linking (commit 4d08439a9cf79f34a730714f12edd5959aae126e) breaks clojure.contrib.repl-ln.

To reproduce, run the following in the standard REPL:
(require 'clojure.contrib.repl-ln) (clojure.contrib.repl-ln/repl)

Expected output (obtained with commit 98366f353463afdc195b9b8fdf9d220bca7d0d6a):
nil
1:2 user=>

Result with commit 4d08439a9cf79f34a730714f12edd5959aae126e:
nil
java.lang.NullPointerException (NO_SOURCE_FILE:0)

The NullPointerException happens in clojure.contrib.repl-ln/prompt-hook where (private :prompt) returns nil.

[CLJ-200] Extend cond to support inline let, much like for

Sun, 2 Dec 2012 19:35:37 -0600

I find it occasionally very useful to do a few tests in a cond, then introduce some new symbols (for both clarity and efficiency) that can be referenced in later tests (or matching expressions). This parallels similar functionality inside the for macro, where the :let keyword is matched against a vector of symbol bindings and forms an implicit let around the remainder of the comprehension.

I'll be adding a patch for this shortly.

[CLJ-190] enhance with-open to be extensible with a new close multimethod

Fri, 23 Dec 2011 06:50:59 -0600

Discussion: http://groups.google.com/group/clojure/browse_thread/thread/8e4e56f6fc65cc8e/618a893a5b2a5410

Currently, with-open calls .close when it's finished. I'd like it to have a (defmulti close type) so it's behavior is extensible. A standard method could be defined for java.io.Closeable and a :default method with no type hint. I've come across a few cases where some external library defines what is essentially a close method but names it shutdown or disable, etc., and adding my own "defmethod close" would be much easier than rewriting with-open. This would also allow people to eliminate reflection for classes like sql Connection that were created before Closeable.

[CLJ-176] structs printed with print-dup true cannot be read

Tue, 24 Aug 2010 06:14:00 -0500

(defstruct thing :a :b)
(def my-thing (struct thing 1 2))
(def s (binding [*print-dup* true] (pr-str my-thing)))
s 
;;=> "#=(clojure.lang.PersistentStructMap/create {:a 1, :b 2})"
(read-string s)
;;=> java.lang.IllegalArgumentException:
;;   No matching method found: create

[CLJ-153] Suggest adding set-precision! API to accompany with-precision

Tue, 24 Aug 2010 00:55:00 -0500

Ticket #137 makes math-context</code> settable at the REPL. However, <code>math-context is not a public name in Clojure.

The related public function is with-precision</code> which works by pushing a new binding for <code>math-context</code>. This ticket suggests adding <code>set-precision!</code> to Clojure's public API. Its effect would be the same as <code>with-precision</code>, but accomplished by using <code>set!</code> on the current <code>math-context binding rather than by pushing a new binding.

Chouser suggests that we also add a doc string for math-context</code> noting that it is private and pointing the user to <code>with-precision</code> and <code>set-precision!. I agree.

[CLJ-150] Doc for array-map should mention its characteristics/caveats

Tue, 24 Aug 2010 04:54:00 -0500

Doc for array-map should mention its characteristics: preserves order of keys, linear O search so appropriate only for small maps, operations on array-maps return hash-maps.

[CLJ-148] Poor reporting of symbol conflicts when using (ns)

Tue, 28 Jun 2011 18:42:50 -0500

I have a module that includes pprint and my own utils.

When com.howard.lewisship.cascade.dom/write was changed from private to public I get the following error:

java.lang.IllegalStateException: write already refers to: #'clojure.contrib.pprint/write in namespace: com.howardlewisship.cascade.test-views (test_views.clj:0)

(ns com.howardlewisship.cascade.test-views ; line 15
(:use
(clojure.contrib test-is pprint duck-streams)
(app1 views fragments)
(com.howardlewisship.cascade config dom view-manager)
com.howardlewisship.cascade.internal.utils))

That line number is wrong but better yet, identifying the true conflict (com.howard.lewisship.cascade.dom/write) would be even more important.

[CLJ-147] Bug: Compile-time NPE on set! of non-existent field [for 1.0]

Mon, 15 Nov 2010 12:49:00 -0600

The bug described in #142 also exists in Clojure 1.0.0

[CLJ-140] Single :tag for type hints conflates value's type with type of return value from an invoke

Tue, 24 Aug 2010 03:51:00 -0500

The value of a Var can be operated on directly, or, if it is a fn, it can be invoked and the resulting value operated on. :tag metadata on a Var is used to provide a type hint to the compiler to avoid reflection. Having a single metadata key for this two distinct uses makes it possible (even easy, if unlikely) to create a situation where type-hinting the value causes a ClassCastException on an operation on the invocation return value, or the reverse. The only obvious solution is two use different keys for the two uses.

[CLJ-132] Agents printed at the REPL do not always reflect their value

Tue, 24 Aug 2010 07:46:00 -0500

Starting with a fresh REPL and entering the following:

(def counter (agent 0))
(defn add1 [x] (inc x))
(send counter add1)
;; repeat many times
(send counter add1)

The representation printed at the REPL will not always display the correct value for the agent (e.g. the second call to `send` would print #<Agent@743fba: 1>). This appears to happen only in the first few calls to `send` before the value eventually "catches up". This behavior of course never occurs with `send-off`. This appears to only affect the printed value and not the actual value, but can still cause confusion.

My setup is as follows:
Mac OSX 10.5
Clojure 1.0.0
Running with `java -server -cp $CP jline.ConsoleRunner clojure.lang.Repl $*` where $CP points to clojure.jar, clojure-contrib.jar, and jline.jar

This also occurs with a fresh build of Clojure 1.1.0-alpha-SNAPSHOT from github.

-m

[CLJ-130] Namespace metadata lost in AOT compile

Fri, 3 Dec 2010 10:48:15 -0600

For example, the namespace @clojure.contrib.def@ has metadata for doc and author.

We see this when we load the file directly from source:
<pre>
<code>
tom@goya:~/src/clj$ java -cp clojure/clojure.jar:clojure-contrib/src clojure.lang.Repl
Clojure 1.1.0-alpha-SNAPSHOT
user=> (load "clojure/contrib/def")
nil
user=> (find-ns 'clojure.contrib.def)
#<Namespace clojure.contrib.def>
user=> ^(find-ns 'clojure.contrib.def)
{:author "Stephen C. Gilardi", :doc "def.clj provides variants of def that make including doc strings and\nmaking private definitions more succinct."}
user=>
</code>
</pre>

But if we load the file from the jar where it's been compiled, the metadata is lost:
<pre>
<code>
tom@goya:~/src/clj$ java -cp clojure/clojure.jar:clojure-contrib/clojure-contrib.jar clojure.lang.Repl
Clojure 1.1.0-alpha-SNAPSHOT
user=> (use 'clojure.contrib.def)
nil
user=> (find-ns 'clojure.contrib.def)
#<Namespace clojure.contrib.def>
user=> ^(find-ns 'clojure.contrib.def)
nil
user=>
</code>
</pre>

Even if we use @load@, we don't see metadata on the item:
<pre>
<code>
tom@goya:~/src/clj$ java -cp clojure/clojure.jar:clojure-contrib/clojure-contrib.jar clojure.lang.Repl
Clojure 1.1.0-alpha-SNAPSHOT
user=> (load "clojure/contrib/def")
nil
user=> (find-ns 'clojure.contrib.def)
#<Namespace clojure.contrib.def>
user=> ^(find-ns 'clojure.contrib.def)
nil
user=>
</code>
</pre>

The jar isn't the problem, for if we use the slim jar (without the AOT
class files), we see that the metadata is fine:
<pre>
<code>
tom@goya:~/src/clj$ java -cp clojure/clojure.jar:clojure-contrib/clojure-contrib-slim.jar clojure.lang.Repl
Clojure 1.1.0-alpha-SNAPSHOT
user=> (use 'clojure.contrib.def)
nil
user=> (find-ns 'clojure.contrib.def)
#<Namespace clojure.contrib.def>
user=> ^(find-ns 'clojure.contrib.def)
{:author "Stephen C. Gilardi", :doc "def.clj provides variants of def that make including doc strings and\nmaking private definitions more succinct."}
user=>
</code>
</pre>

This seems to be true usually, but not always. For example the
metadata on the pretty print namespace is just fine from the AOT version:
<pre>
<code>
tom@goya:~/src/clj$ java -cp clojure/clojure.jar:clojure-contrib/clojure-contrib.jar clojure.lang.Repl
Clojure 1.1.0-alpha-SNAPSHOT
user=> (use 'clojure.contrib.pprint)
nil
user=> (find-ns 'clojure.contrib.pprint)
#<Namespace clojure.contrib.pprint>
user=> ^(find-ns 'clojure.contrib.pprint)
{:author "Tom Faulhaber", :doc "This module comprises two elements:\n1) A pretty printer for Clojure data structures, implemented in the function \"pprint\"\n2) A Common Lisp compatible format function, implemented as \"cl-format\" because\n Clojure is using the name \"format\" for its own format.\n\nComplete documentation is available on the wiki at the contrib google code site.", :see-also [["PrettyPrinting" "Documentation for the pretty printer"] ["CommonLispFormat" "Documentation for Common Lisp format function"]]}
user=>
</code>
</pre>

[CLJ-129] Add documentation to sorted-set-by detailing how the provided comparator may change set membership semantics

Tue, 24 Aug 2010 07:45:00 -0500

To start, let's look at some simple default sorted-set behaviour (which uses PersistentHashMap via PersistentHashSet, and therefore uses equality/hashCode to determine identity):

user=> (sorted-set [1 2] [-5 10] [1 5])
#{[-5 10] [1 2] [1 5]}
</code></pre>

sorted-set-by uses PersistentTreeMap via PersistentTreeSet though, which implies that the comparator provided to sorted-set-by will be used to determine identity, and therefore member in the set.  This can lead to (IMO) non-intuitive behaviour:

<pre><code>
user=> (sorted-set-by #(> (first %) (first %2)) [1 2] [-5 10] [1 5])
#{[1 2] [-5 10]}

Notice that because the provided comparison fn determines that [1 2] and [1 5] have the same sort order, the latter value is considered identical to the former, and not included in the set. This behaviour could be very handy, but is also likely to cause confusion when what the user almost certainly wants is to maintain the membership semantics of the original set (e.g. relying upon equality/hashCode), but only modify the ordering.

(BTW, yes, I know there's far easier ways to get the order I'm indicating above over a set of vectors thanks to vectors being comparable via the compare fn. The examples are only meant to be illustrative. The same non-intuitive result would occur, with no easy fallback (like the 'compare' fn when working with vectors) when the members of the set are non-Comparable Java object, and the comparator provided to sorted-set-by is defining a sort over some values returned by method calls into those objects.)

I'd be happy to change the docs for sorted-set-by, but I suspect that there are others who could encapsulate what's going on here more correctly and more concisely than I.

[CLJ-126] abstract superclass with non-public accessibility

Tue, 24 Aug 2010 04:45:00 -0500

The following code works in Java 6 but not in Java 5:

(def Clojure 1.1.0-alpha-SNAPSHOT
user=> (def s (new StringBuilder "aaa"))
#'user/s
user=> (. s setCharAt (int 0) (char \a))
java.lang.Exception: Unable to resolve symbol: setCharAt in this context

This was discussed on the Clojure mailing list and Stephen C. Gillardi came up with the following conclusion:

_StringBuilder extends AbstractStringBuilder (though the JavaDoc docs lie and say it extends Object). AbstractStringBuilder has default accessibility (not public, protected, or private) which makes the class inaccessible to code outside the java.lang package. In both Java SE 5 and Java SE 6, StringBuilder does not contain a .setCharAt method definition. It relies on the inherited public method in AbstractStringBuilder. (I downloaded the source code for both versions from Sun to check.)

In Java SE 5, when Clojure checks whether or not .setCharAt on StringBuilder is public, it finds that it's a public method of a non-public base class and throws the exception you saw. (It looks like you're using a version of Clojure older than 18 May 2009 (Clojure svn r1371). Versions later than that print the more detailed message I saw.)

In Java SE 6, Clojure's checks for accessibility of this method succeed and the method call works.

I'm not sure whether or not Clojure could be modified to make this method call work in Java 5. Google searches turn up discussion that this pattern of using an undocumented abstract superclass with non-public accessibility is not common in the JDK._

This ticket is being filed in the event that Clojure can handle these types of situations somehow.

[CLJ-122] GC Issue 118: Patch to add :svn to clojure-version

Tue, 24 Aug 2010 06:45:00 -0500

Reported by miki.tebeka, May 16, 2009

Attached is a patch to add :svn to *clojure-version*.
In order for it to work do "svn ps svn:keywords Revision
src/clj/clojure/core.clj"

This way when people report problem in clojure, we can know the exact
revision they are talking about.

[CLJ-121] GC Issue 117: FAQ Page has formatting errors

Fri, 13 Apr 2012 08:02:57 -0500

Reported by miki.tebeka, May 13, 2009

The FAQ page (http://code.google.com/p/clojure/wiki/FAQ) has several
formatting errors:

* "How do I call a Java method that takes a variable number of arguments?"
is missing a space to make it a header.
* The link to SICP showing the URL

[CLJ-120] GC Issue 116: partition with pad

Fri, 2 Dec 2011 12:17:05 -0600

Reported by dimi...@gashinsky.com, May 09, 2009

;; A lot of times I needed a padding option on the partition. This is
;; my attempt to solve this problem. Any suggestions are welcome. I
;; hope this patch or something similar will make its way into the
;; core.

Some discussion that happened here:
http://groups.google.com/group/clojure/browse_frm/thread/6fcc1dd999a5ec02?tvc=1
was integrated into the patch.

[CLJ-118] GC Issue 114: version.properties in branch/1.0 is inaccurate

Fri, 20 Jul 2012 16:55:35 -0500

Reported by hlship, May 04, 2009

The version.properties in the 1.0 branch generates snapshot releases.
Ideally, there should be a tags/1.0 branch that locks down the 1.0 release.
Context: trying to build a 1.0 release artifact for the Maven repository.

Comment 1 by richhickey, May 04, 2009

Do you believe this advice was erroneous?

http://groups.google.com/group/clojure/msg/cb46994561dbc732

Comment 2 by hlship, May 05, 2009

I'm bothered that the 1.0 release is a 1.0 release, but not really.  Either its a
final release or its not. Saying its still a snapshot when you've broadcasted to the
world that its final seems very odd to me.

On the mailing list, I espoused the "Apache Way", which is to not get hung up on a
"1.0.0" number, but keep releasing.  If "1.0.2" has bugs, fix them and release
"1.0.3".  If that is finally stable, announce "Clojure 1.0 is version 1.0.3". Let the
release prove itself valid.

Older Tapestry releases were based on the "line in the sand" approach ... and always
ended up requiring a flurry of dot release bug fixes.

[CLJ-115] GC Issue 111: Enable naming an array parameter for areduce

Tue, 24 Aug 2010 05:45:00 -0500

Reported by bo...@boriska.com, Apr 28, 2009

Currently there is no way to access anonymous array parameter of areduce.

Consider:

(areduce (.. System getProperties values toArray) 
     i r 0 (some_expression))
some_expression has no way to access the array.

Per Rich:
--------------------
Yes, areduce would be nicer if it looked like a binding set:

(areduce [aname anarray, ret init] expr)
(areduce [aname anarray, ret init, start-idx  start-n] expr)
(areduce [aname anarray, ret init, start-idx  start-n, end-idx end-n]
expr) 
--------------------

This was discussed here:
http://groups.google.com/group/clojure/tree/browse_frm/thread/40597a8ac322bc37/8cf6b17328ea7e8b?rnum=1&_done=%2Fgroup%2Fclojure%2Fbrowse_frm%2Fthread%2F40597a8ac322bc37%2F8cf6b17328ea7e8b%3Ftvc%3D1%26pli%3D1%26#doc_9ea7e3c5d500ed3c

[CLJ-114] GC Issue 110: clojure version number patch

Tue, 24 Aug 2010 00:45:00 -0500

Reported by laurent....@gmail.com, Apr 26, 2009

Patch with the necessary changes to handle version numbering for clojure:

 * a src/clj/clojure/version.properties file
 * this version.properties file is the reference for version numbers. It is
on the classpath so it can be seen by clojure at runtime. It is in a
subdirectory of clojure-the-project so any tool can refer to it relatively
to the installation of clojure.

 * I've added the necessary code to clojure to load clojure version number
at startup time


I've also added function (clojure.core/clojure-version) that will return a
string representing the version from the structured *clojure-version* map.
The algorithm here is simple: 
<MAJOR>.<MINOR>[.<INCREMENT>][-<QUALIFIER>][-SNAPSHOT]

 * I've changed the ant build.xml so that it creates fully qualified names
with version attributes for the generated jars.
 * Note on the :interim attribute: to protect the person who makes releases
from itself, instead of considering :interim to be true if there is the
"true" string in the properties file, I've made the opposite choice:
interim is true for any value other than "false". So if there is a typo in
version.properties (e.g. tru instead of true), then the release will be
marked as interim, and that will not be a big deal. In the other case, it
would be a big deal if an official release was made accidentally instead of
an interim.

* finally, pom.xml file is now generated from ant as part of the classic
init step.

Note: I strongly suggest that the clojure.version.interim property remains
true in svn, so that it's not possible to inadvertently release a version
"too early".

Comment 1  by richhickey, Apr 27, 2009

I can't apply the patch due to missing pom-template.xml?

Also, could you just put the contents of core_version.clj into core.clj? I'd rather
not have another file just for this.

Thanks!

Comment 2 by laurent....@gmail.com, Apr 27, 2009

OK, core_version.clj content back into core.clj.

There was a problem with pom-template.xml probably because I tried on my local
working copy to make a svn rename pom.xml pom-template.xml, and somehow the svn diff
command did not like that.

What I've done in the current patch is first svn remove pom.xml then svn add
pom-template.xml.

Comment 3  by richhickey, Apr 27, 2009

patch applied- svn 1357 - thanks!

Status: Accepted
Comment 4 by scgilardi, May 12, 2009

(clojure-version) for 1.0 has a trailing "-". The intention (as noted above in the
issue) is that when the qualifier is absent, there should be no "-". The current
setup is reading a blank qualifier as an empty string, but checking later for nil
rather than nil or the empty string.

Clojure 1.0.0-
user=> *clojure-version*
{:major 1, :minor 0, :incremental 0, :qualifier ""}
user=> (clojure-version)
"1.0.0-"
user=> 



Comment 5 by laurent....@gmail.com, May 12, 2009

OK, a mistake on my part.

Rich, I also see you have made implicitly the "incremental" attribute mandatory in
trunk (since you apply Integer/valueOf on it without checking for nullity or string
emptyness).

If it is intentional, I can also add in the corrective patch a modified build.xml
that verifies this (incremental being mandatory) when building with ant, or I can
change the patch to keep the "incremental" attribute optional.

Waiting for your answer before creating the patch.

[CLJ-112] GC Issue 108: All Clojure interfaces should specify CharSequence instead of String when possible

Tue, 24 Aug 2010 03:45:00 -0500

Reported by redchin, Apr 20, 2009

rhickey: unlink: then just use a map {:escaped true :val "foo"}

unlink: What I meant is, everything in between would want to see something 
String-y, not caring whether it's a String or MyString.

hiredman: unlink: if you use something that implements CharSequence and 
IMeta (I think it's IMeta) you get something that is basically a String, 
but with metadata

rhickey: what hiredman said

hiredman: ideally most things would not specify String but CharSequence in 
their interface

hiredman: but somehow I doubt that is case

unlink: ok.

unlink: Good to know.

rhickey: hiredman: unfortunately that's not true of some of Clojure - could 
you enter an issue for it please - use CharSequence when possible?

[CLJ-107] GC Issue 103: bit-count function

Thu, 15 Nov 2012 20:40:50 -0600

Reported by a...@thened.net, Apr 08, 2009

I posted this small patch to the mailing list last week but received no
feedback, so I'm attaching it here to make sure it doesn't get lost.  I
have submitted a CA.

http://groups.google.com/group/clojure/browse_thread/thread/4345f76a12bac6fe/

The new function bit-count returns the count of 1-bits in a number, like
C's popcount or Common Lisp's logcount.

[CLJ-99] GC Issue 95: max-key and min-key evaluate k multiple times for arguments

Thu, 15 Nov 2012 21:36:54 -0600

Reported by H.Duerer, Mar 13, 2009

max-key or min-key will evaluate (k value) multiple times for arguments if
more than 2 arguments are passed.

This is undesirable if k is expensive to calculate.

Something like the code below would avoid these double calculations (at the
price of generating more ephemeral garbage)

(defn max-key
  "Returns the x for which (k x), a number, is greatest."
  ([k x] x)
  ([k x y] (if (> (k x) (k y)) x y))
  ([k x y & more]
     (second (reduce (fn [x y] (if (> (first x) (first y)) x y))
                     (map #(vector (k %) %) (cons x (cons y more)))))))

[CLJ-89] GC Issue 85: In a defn, arglists metadata becomes the first (unexpected?) symbol

Tue, 24 Aug 2010 03:45:00 -0500

Reported by jochu0, Feb 22, 2009

> What (small set of) steps will reproduce the problem?

(:arglists (meta (defn arglists broken-arglist ([a] a) ([a b] b))))
(broken-arglist)

> What is the expected output? What do you see instead?

I would expect ([a] [a b]) if not an error.

> What version are you using?

Using the latest clojure (r1298) and also likely to exist before lazy-seq.

> Was this discussed on the group? If so, please provide a link to the
discussion:

http://groups.google.com/group/clojure/browse_thread/thread/bafdb169330a9344

[CLJ-87] GC Issue 83: PersistentArrayMap trust the reader (map literals) too much

Tue, 24 Aug 2010 00:45:00 -0500

Reported by karmazilla, Feb 17, 2009

What (small set of) steps will reproduce the problem?

PersistentArrayMap gets it wrong:

user=> {1 1 1 1 1 1 2 2}
{1 1, 1 1, 1 1, 2 2}

What is the expected output? What do you see instead?

But PersistentHashMap gets it right:

user=> (hash-map 1 1 1 1 1 1 2 2)
{1 1, 2 2}

What version are you using?

rev 1286.

Was this discussed on the group? If so, please provide a link to the 
discussion:
http://groups.google.com/group/clojure/browse_thread/
thread/5a38a6b61b09e025

Please provide any additional information below.

PersistentArrayMap seems to be the culprits. Line 65 to 73. They should 
probably assoc the individual items like PersistentHashMap do, I guess.

[CLJ-77] GC Issue 74: Clojure compiler emits too-large classfiles (results in ClassFormatError)

Tue, 24 Aug 2010 06:45:00 -0500

Reported by cemer...@snowtide.com, Feb 10, 2009

The jvm has certain implementation limits around the maximum size of
classfiles, literal strings, method length, etc; however, in certain
circumstances, the Clojure compiler can currently emit classfiles that
violate some of those limitations, causing an error later when the
classfile is loaded.

While test coverage would necessarily detect this sort of problem on a
project-by-project basis when one's tests attempted to load a project's
classfiles, it seems like Clojure should do the following to ensure failure
as quickly as possible:

- throw an exception immediately if, while compiling a lib, it is detected
that the resulting classfile(s) would violate any classfile implementation
limits.  Ideally, the exception's message would detail what file and on
which line number the offending form is (e.g. if a method's bytecode would
be too long).  I can imagine that doing this may not be straightforward; a
reasonable stop-gap would be for the compiler to immediately attempt to
load the generated classfile in order to ensure up-front failure.

- emit a warning if any clojure form is read that would, upon being
compiled, require violating any of the classfile implementation limits; I
suspect that *most* people looking to generate classfiles would be doing so
in a "build" environment (rather than loading some code, tinkering, and
then using clojure.core/compile), but for those that aren't, I can imagine
there being a good deal of frustration around seeing that loading and using
some code successfully would eventually produce unusable classfiles.

I've appended a sample stack trace emitted by java when it attempted to
load a too-long method implementation (which was produced by embedding a
large list literal in a compiled lib).

Exception in thread "main" java.lang.ClassFormatError: Invalid method  
Code length 105496 in class file com/foo/MyClass__init
         at java.lang.ClassLoader.defineClass1(Native Method)
         at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
         at  
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
         at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
         at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
         at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
         at java.security.AccessController.doPrivileged(Native Method)
         at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
         at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:
288)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
         at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:
374)
         at java.lang.Class.forName0(Native Method)
         at java.lang.Class.forName(Class.java:247)
         at clojure.lang.RT.loadClassForName(RT.java:1512)
         at clojure.lang.RT.load(RT.java:394)
         at clojure.lang.RT.load(RT.java:374)
         at clojure.core$load__4911$fn__4913.invoke(core.clj:3623)
         at clojure.core$load__4911.doInvoke(core.clj:3622)
         at clojure.lang.RestFn.invoke(RestFn.java:413)
         at clojure.core$load_one__4863.invoke(core.clj:3467)
         at clojure.core$compile__4918$fn__4920.invoke(core.clj:3633)
         at clojure.core$compile__4918.invoke(core.clj:3632)
         at clojure.lang.Var.invoke(Var.java:336)
         at clojure.lang.Compile.main(Compile.java:56)

[CLJ-64] GC Issue 61: Make Clojure datatype Java Serializable

Tue, 24 Aug 2010 14:44:00 -0500

Reported by straszheimjeffrey, Jan 30, 2009

I mentioned this on Google Groups.

Currently the core Clojure datatypes are not Java Serializable.  This means
that they cannot easily be streamed as binary objects.  Also, it will be
difficult to use them with certain Java features like RMI.

Comment 1 by rob.nikander, Mar 11, 2009

I voted for this because I'm experimenting with using Clojure for web apps.  Tomcat barfs trying to serialize 
objects in the session, like clojure.lang.Cons.

Comment 2 by cjkent, Mar 25, 2009

I'm experimenting with Clojure and Wicket.  Any Wicket page classes containing maps
that use Keywords as keys can't be saved to the session because Keyword isn't
serializable.

[CLJ-61] GC Issue 57: Compiler internal error when expanding macro: class not found

Tue, 24 Aug 2010 03:44:00 -0500

Reported by tuomas.lukka, Jan 29, 2009
 
------------------------------

What (small set of) steps will reproduce the problem?

Run the following code:

(defmacro b [] (let [ x (fn [] []) ] x))
(def a (fn [] (b)))


What is the expected output? What do you see instead?

I'd expect it to either pass or give a proper error. What I get
is

Exception in thread "main" java.lang.ExceptionInInitializerError (test.clj:2)
 at clojure.lang.Compiler$DefExpr.eval(Compiler.java:308)
 at clojure.lang.Compiler.eval(Compiler.java:4147)
 at clojure.lang.Compiler.load(Compiler.java:4470)
 at clojure.lang.Compiler.loadFile(Compiler.java:4437)
 at clojure.lang.Script.main(Script.java:65)
Caused by: java.lang.ExceptionInInitializerError
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
 at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
 at java.lang.Class.newInstance0(Class.java:355)
 at java.lang.Class.newInstance(Class.java:308)
 at clojure.lang.Compiler$FnExpr.eval(Compiler.java:3218)
 at clojure.lang.Compiler$DefExpr.eval(Compiler.java:297)
 ... 4 more
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException:
clojure.core$b__1$x__3
 at clojure.lang.RT.readString(RT.java:1192)
 at clojure.core$a__7.<clinit>(test.clj:2)
 ... 12 more
Caused by: java.lang.ClassNotFoundException: clojure.core$b__1$x__3
 at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
 at clojure.lang.DynamicClassLoader.findClass(DynamicClassLoader.java:52)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
 at java.lang.Class.forName0(Native Method)
 at java.lang.Class.forName(Class.java:247)
 at clojure.lang.RT.classForName(RT.java:1506)
 at clojure.lang.LispReader$EvalReader.invoke(LispReader.java:908)
 at clojure.lang.LispReader$DispatchReader.invoke(LispReader.java:530)
 at clojure.lang.LispReader.read(LispReader.java:143)
 at clojure.lang.RT.readString(RT.java:1188)
 ... 13 more


What version are you using?

20081217

Was this discussed on the group? If so, please provide a link to the
discussion:

no

[CLJ-50] GC Issue 46: callable defstruct (PersistentStructMap$Def extends AFn)

Mon, 15 Nov 2010 08:14:04 -0600

Reported by chouser, Jan 15, 2009
Describe the feature/change.

This much works already:
(defstruct rect :width :height)
(struct rect 5 10)  ==> {:width 5, :height 10}

With the included patch you can also:
(rect 5 10)  ==> {:width 5, :height 10}

Was this discussed on the group? If so, please provide a link to the
discussion:

http://groups.google.com/group/clojure/browse_thread/thread/12a138ad58ff6c36/b20b68ef939fccf7

Comment 1 by chouser, Jan 15, 2009
Forgot the patch attachment.
 structmap-def-extends-restfn.patch
923 bytes Download

[CLJ-21] GC Issue 17: arity checking during compilation

Tue, 24 Aug 2010 14:44:00 -0500

Reported by richhickey, Dec 17, 2008
Use available metadata to check calls when possible

[CLJ-19] GC Issue 15: JavaDoc for interfaces

Sat, 17 Nov 2012 20:05:58 -0600

Reported by richhickey, Dec 17, 2008
Add JavaDoc to those interfaces supported for public use - IFn,
IPersistentCollection etc.

[CLJ-17] GC Issue 13: validate in (keyword s) and (symbol s)

Fri, 7 Oct 2011 08:03:06 -0500

Reported by richhickey, Dec 17, 2008
Make sure they create readable keywords/symbols

Comment 1 by p...@hagelb.org, Apr 27, 2009
Could this be done with a regex, or should it try to confirm the name using the reader?
Comment 2 by p...@hagelb.org, Apr 27, 2009
I've implemented this in the attached patch. One thing that could be improved is that
invalid names simply raise an Exception, though it seems LispReader's ReaderException
would be more appropriate. I wasn't sure how to raise that though since it needs a
line number; it's not clear how to get the current line number.

The patch is still an improvement on the current state of things, though I'd
appreciate a tip as to how to raise the right exception.

I've also attached a patch to the test suite that ensures (symbol s) and (keyword s)
work properly in the context of invalid names. I can re-submit this to the contrib
project if that's desired if the core patch is accepted.
 0001-Test-invalid-symbol-keyword-names-raise-exceptions.patch
1.6 KB Download
Comment 3 by p...@hagelb.org, Apr 27, 2009
Last patch had a problem; used things like defn- etc. before they were defined in
core.clj. This attachment fixes that.
 validate-symbol-keyword-names.patch
2.1 KB Download
Comment 4 by p...@hagelb.org, Jun 13 (3 days ago)
This exists as a git branch too now: 
http://github.com/technomancy/clojure/tree/validate-symbols-issue-13

[CLJ-15] GC Issue 11: incremental hashcode calculation for collections

Fri, 8 Mar 2013 06:20:08 -0600

Reported by richhickey, Dec 17, 2008
So hachCode can be final, more efficient to calc as you go.

[CLJ-5] Unintuitive error response in clojure 1.0

Sat, 28 Apr 2012 22:48:40 -0500

The following broken code:

(let [[x y] {}] x)

provides the following stack trace:

Exception in thread "main" java.lang.UnsupportedOperationException: nth not supported on this type: PersistentArrayMap (test.clj:0)
at clojure.lang.Compiler.eval(Compiler.java:4543)
at clojure.lang.Compiler.load(Compiler.java:4857)
at clojure.lang.Compiler.loadFile(Compiler.java:4824)
at clojure.main$load_script__5833.invoke(main.clj:206)
at clojure.main$script_opt__5864.invoke(main.clj:258)
at clojure.main$main__5888.doInvoke(main.clj:333)
at clojure.lang.RestFn.invoke(RestFn.java:413)
at clojure.lang.Var.invoke(Var.java:346)
at clojure.lang.AFn.applyToHelper(AFn.java:173)
at clojure.lang.Var.applyTo(Var.java:463)
at clojure.main.main(main.java:39)
Caused by: java.lang.UnsupportedOperationException: nth not supported on this type: PersistentArrayMap
at clojure.lang.RT.nth(RT.java:800)
at clojure.core$nth__3578.invoke(core.clj:873)
at user$eval__1.invoke(test.clj:1)
at clojure.lang.Compiler.eval(Compiler.java:4532)
... 10 more

The message "nth not supported on this type" while correct doesn't make the cause of the error very clear. Better error messages when destructuring would be very helpful.

Clojure JIRA

[CLJ-826] Include drop, take, butlast from clojure.contrib.string (1.2) in clojure.string 1.3

[CLJ-821] should reify merge rather than replace on repeated specs?

[CLJ-806] clojure.test/are does not fail with insufficient arguments

[CLJ-785] Optimize /

[CLJ-771] Move unchecked-prim casts to clojure.unchecked

[CLJ-761] print-dup generates call to nonexistent method for APersistentVector$SubVector

[CLJ-732] (keyword "") can be printed, but not read

[CLJ-720] check that argument to keys/vals is a Map

[CLJ-698] class accessible from deftype method bodies is not suitable for instance?, ...

[CLJ-466] Reflection incorrectly avoids "More than one matching method" exceptions

[CLJ-464] RFE: Run FindBugs on Clojure source code

[CLJ-463] Strip leading colons when creating keywords from single strings

[CLJ-461] require namespace implicitly

[CLJ-459] RFE: modify description of "assoc"

[CLJ-455] Calculating large numbers results in java.math.BigIntegerArithmeticException

[CLJ-451] fn literals lack name/arglists/namespace metadata

[CLJ-450] Add default predicate argument to filter, every?, take-while

[CLJ-449] NullPointerException in clojure.stacktrace

[CLJ-446] 1.3 alpha1 gives reflection warning in a case where 1.2 does not

[CLJ-440] java method calls cannot omit varargs

[CLJ-438] case* and code walkers

[CLJ-436] Bug in clojure.contrib.json/read-json

[CLJ-434] Additional copy methods for URLs in clojure.java.io

[CLJ-431] with-junit-output should use with-test-out when writing header and testsuites tags

[CLJ-424] instance? fails on deftype instance, when used from multiple files

[CLJ-419] LispReader uses Character.isWhitespace rather than Character.isSpaceChar

[CLJ-416] improvments on agent

[CLJ-414] In latest clojure, empty list is neither true nor false

[CLJ-412] clojure.xml/emit, emit-element are not documented at clojure.org

[CLJ-411] clojure.xml/emit should be encoding-aware

[CLJ-409] SAXParserFactoryImpl is missing at unit testing time

[CLJ-408] clojure.xml emit does not properly escape attribute and element content

[CLJ-406] Typo in underive causes breaking in the resulting hierarchy

[CLJ-405] better error messages for bad defrecord calls

[CLJ-401] Promote "seqable?" from contrib?

[CLJ-400] A faster flatten

[CLJ-396] Better support for multiple inheritance in hierarchies and multimethods

[CLJ-395] "underive" corrupts ad hoc hierarchies.

[CLJ-379] problem with classloader when run as windows service

[CLJ-375] metadata literal enhancements

[CLJ-363] defn doesn't put the right metadata on its fn value

[CLJ-354] <= and >= comparisons against NaN return true

[CLJ-350] namespace function NPE if namespace does not exist

[CLJ-346] (pprint-newline :fill) is not handled correctly

[CLJ-345] clojure.contrib.string.replace-str throws NPE on nil string

[CLJ-339] Integer autopromotion error

[CLJ-319] TransactionalHashMap bug

[CLJ-308] protocol-ize with-open

[CLJ-304] contrib get-source no longer works with deftype

[CLJ-293] doto doc minor typo

[CLJ-288] Make clojure.core/merge-with accept a wider range of map types

[CLJ-287] (take-nth 0 coll) spins wheels on Solaris

[CLJ-284] Cannot cast 0xFF to a byte (fails range check)

[CLJ-283] recur ignores rest args

[CLJ-279] Numbers as keys in maps must be of the same class to match

[CLJ-277] Making clojure.xml/emit a little friendler to xml consumers

[CLJ-274] cannot close over mutable fields (in deftype)

[CLJ-273] def with a function value returns meta {:macro false}, but def itself doesn't have meta

[CLJ-272] load/ns/require/use overhaul

Minimal needs

Other possibilities to discuss.

[CLJ-255] add denominator and numerator fns for Ratio

[CLJ-251] macroexpand should respect :inline

[CLJ-238] Make re-pattern accept multiple arguments to concatenate them.

[CLJ-237] Adding a :only-keys destructuring option, that throws an exception if there's extra key(s).

[CLJ-233] better error reporting of nonexistent var

[CLJ-213] Invariants and the STM

[CLJ-212] Direct linking breaks clojure.contrib.repl-ln.

[CLJ-200] Extend cond to support inline let, much like for

[CLJ-190] enhance with-open to be extensible with a new close multimethod

[CLJ-176] structs printed with *print-dup* true cannot be read

[CLJ-153] Suggest adding set-precision! API to accompany with-precision

[CLJ-150] Doc for array-map should mention its characteristics/caveats

[CLJ-148] Poor reporting of symbol conflicts when using (ns)

[CLJ-147] Bug: Compile-time NPE on set! of non-existent field [for 1.0]

[CLJ-140] Single :tag for type hints conflates value's type with type of return value from an invoke

[CLJ-132] Agents printed at the REPL do not always reflect their value

[CLJ-130] Namespace metadata lost in AOT compile

[CLJ-129] Add documentation to sorted-set-by detailing how the provided comparator may change set membership semantics

[CLJ-176] structs printed with print-dup true cannot be read

[CLJ-122] GC Issue 118: Patch to add :svn to clojure-version