Recent Activity (Clojure JIRA)

[CLJ-827] unsigned-bit-shift-right

Fri, 24 May 2013 14:24:09 -0500

Add a clojure equivalent of >>>.

A simple version of this is implemented here (https://github.com/joegallo/clojure/tree/unsigned-bit-shift-right), and just follows the example set by shift-right.

The downside of this implementation is that it treats all integer types as longs, and shifts them accordingly, which yields different results than you would get in java. A previous version of this did not have the same problem, when BitOps was its own thing. I'm not sure if this limitation is acceptable and appropriate, or needs to be worked around (my inclination is the latter).

[CLJ-322] Enhance AOT compilation process to emit classfiles only for explicitly-specified namespaces

Fri, 24 May 2013 13:25:25 -0500

Summary: still needs decision on implementation approach.

This was originally/erroneously reported by Howard Lewis Ship in the clojure-contrib assembla:

My build file specifies the namespaces to AOT compile but if I include another namespace
(even from a JAR dependency) that is not AOT compiled, the other namespace will be compiled as well.

In my case, I was using clojure-contrib's clojure.contrib.str-utils2 namespace, and I got a bunch of
clojure/contrib/str_utils2 classes in my output directory.

I think that the AOT compiler should NOT precompile any namespaces that are transitively reached,
only namespaces in the set specified by the command line are appropriate.

As currently coded, you will frequently find unwanted third-party dependencies in your output JARs;
further, if multiple parties depend on the same JARs, this could cause bloating and duplication in the
eventual runtime classpath.

Having the option of shipping either all AOT-compiled classfiles or mixed source/AOT depending upon one's distribution requirements would make that phase of work with a clojure codebase significantly easier and less error-prone. The only question in my mind is what the default should be. We're all used to the current behaviour, but I'd guess that any nontrivial project where the form of the distributable matters (i.e. the source/AOT mix), providing as much control as possible by default makes the most sense. Given the tooling that most people are using, it's trivial (and common practice, IIUC) to provide a comprehensive list of namespaces one wishes to compile, so making that the default shouldn't be a hurdle to anyone. If an escape hatch is desired, a --transitive switch to clojure.lang.Compile could be added.

[CLJ-1016] Global scope overrides lexical scope for classes (Clojure assumes no classes in default package / Clojure cannot handle yFiles JARs in classpath)

Fri, 24 May 2013 13:21:28 -0500

The most visible symptom of this bug is having a class named 'w' (default package) in your classpath (such classes are produced by Java obfuscation tools such as yFiles) and then attempting to load Clojure's core class. For example:

java -cp hotspotapi.jar:clojure-1.4.0-slim.jar clojure.main

(where hotspotapi.jar is a stereotypical example of an obfuscated JAR) results in:

Exception in thread "main" java.lang.ExceptionInInitializerError
at clojure.main.<clinit>(main.java:20)
Caused by: java.lang.NoSuchFieldException: close, compiling:(clojure/core.clj:6139)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6462)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$TryExpr$Parser.parse(Compiler.java:2178)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5919)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5618)
at clojure.lang.Compiler$FnMethod.parse(Compiler.java:5054)
at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3674)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6453)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6443)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.access$100(Compiler.java:37)
at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:518)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
at clojure.lang.Compiler.analyze(Compiler.java:6262)
at clojure.lang.Compiler.analyze(Compiler.java:6223)
at clojure.lang.Compiler.eval(Compiler.java:6515)
at clojure.lang.Compiler.load(Compiler.java:6952)
at clojure.lang.RT.loadResourceScript(RT.java:359)
at clojure.lang.RT.loadResourceScript(RT.java:350)
at clojure.lang.RT.load(RT.java:429)
at clojure.lang.RT.load(RT.java:400)
at clojure.lang.RT.doInit(RT.java:436)
at clojure.lang.RT.<clinit>(RT.java:318)
... 1 more
Caused by: java.lang.NoSuchFieldException: close
at java.lang.Class.getField(Class.java:1537)
at clojure.lang.Compiler$StaticFieldExpr.<init>(Compiler.java:1180)
at clojure.lang.Compiler$HostExpr$Parser.parse(Compiler.java:923)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6455)
... 37 more
Could not find the main class: clojure.main. Program will exit.

To understand what is going on, consider this simple test:

import java.io.StringReader;

import clojure.lang.Compiler;
import clojure.lang.RT;

public class Test {
public static void main(String[] args) { RT.var("clojure.core", "require"); String s = "(let [mumble (new java.io.StringReader \"\")] (. mumble close))"; Compiler.load(new StringReader(s)); }
}

It should be clear that 'mumble' in the dot operator is referencing the locally defined mumble. However, if we define a class named 'mumble' in the default package, Clojure picks that one up instead.

To forestall any objections: yes, we know that placing classes in the default package is extremely poor form. Point of the matter is, the Java ecosystem is extremely diverse and there are a lot of JARs people may not have control over. While one might argue, "Don't put classes in the default namespace", point of the matter is, Clojure is wrong here, and these situations arise in practice, through no fault of the implementer.

[CLJ-1074] Read/print round-trip for +/-Infinity and NaN

Fri, 24 May 2013 13:11:13 -0500

A few float-related forms (namely, Double/POSITIVE_INFINITY, Double/NEGATIVE_INFINITY, Double/NaN) are not eval-able after a round-trip via

(read-string (binding [*print-dup* true] (pr-str f))

The two options I see are to provide print-method implementations for these and their Float cousins, or to make Infinity, -Infinity, +Infinity, and NaN readable values. Since it sounds like edn may want to provide a spec for these values (see https://groups.google.com/d/topic/clojure-dev/LeJpOhHxESs/discussion and https://github.com/edn-format/edn/issues/2), I think making these values directly readable as already printed is preferable. Something like Double/POSITIVE_INFINITY seems too low-level from edn's perspective, as it would refer to a Java class and constant.

I'm attaching a patch implementing reader support for Infinity, -Infinity, +Infinity, and NaN.

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

Fri, 24 May 2013 12:45:25 -0500

NIO Channels reduce CPU/Disk load when copying Files (by using
syscalls like sendfile internally on Linux/Solaris).

CPU-Load goes from 100% to 0% on my system when copying large files, because no userspace-copying is involved:

Patch: http://github.com/juergenhoetzel/clojure/commit/2b5ab103cbcfe6c49236ac6966c032d3c922233d

[CLJ-1107] 'get' should throw exception on non-Associative argument

Fri, 24 May 2013 12:31:42 -0500

The implementation of clojure.core/get returns null if its argument is not a valid associative collection. However, calling 'get' on something which is neither nil nor an Associative collection is almost certainly a bug, and should be indicated by an exception.

This behavior can obscure common programmer errors such as:

(def a (atom {:a 1 :b 2})

(:foo a)   ; forgot to deref a
;;=> nil

~~CLJ-932~~ was accepted as a similar enhancement to 'clojure.core/contains?'

Attached patch 0001 throws an IllegalArgumentException as the fall-through case of RT.getFrom.

[CLJ-850] Hinting the arg vector of a primitive-taking fn with a non-primitive type results in AbstractMethodError when invoked

Fri, 24 May 2013 12:12:20 -0500

Summary: The CLJ-850-conform-to-invokePrim.diff patch is constructed per Rich's feedback, and appears good to me [Stu].

See the following examples:

user=> (defn f1 ^String [^String s] s)
#'user/f1
user=> (f1 "foo")
"foo"
user=> (defn f2 ^long [^String s ^long i] i)
#'user/f2
user=> (f2 "foo" 1)
1
user=> (defn f3 ^String [^String s ^long i] s)                                       
#'user/f3
user=> (f3 "foo" 1)
AbstractMethodError user$f3.invokePrim(Ljava/lang/Object;J)Ljava/lang/Object;  user/eval8 (NO_SOURCE_FILE:6)

[CLJ-1193] bigint, biginteger throw on double values outside of long range

Fri, 24 May 2013 11:46:12 -0500

This works fine:

user> (bigint (* 0.99 Long/MAX_VALUE))
9131138316486227968N

but this and any other Float or Double values outside the range of a
long throw an exception:

user> (bigint (* 1.01 Long/MAX_VALUE))
IllegalArgumentException Value out of range for long: 9.315605757223324E18 clojure.lang.RT.longCast (RT.java:1178)

Similarly for biginteger

[CLJ-1125] Clojure can leak memory when used in a servlet container

Fri, 24 May 2013 11:36:08 -0500

When used within a servlet container
(Jetty/Tomcat/JBossAS/Immutant/etc), the thread locals Var.dvals (used
to store dynamic bindings) and LockingTransaction.transaction (used to
store the currently active transaction(s)) prevent all of the classes
loaded by an application's clojure runtime from being garbage collected,
resulting in a memory leak.

The issue comes from threads living beyond the lifetime of a
deployment - servlet containers use thread pools that are shared
across all applications within the container. Currently, the dvals and
transaction thread locals are not discarded when they are no longer
needed, causing their contents to retain a hard reference to their
classloaders, which, in turn, causes all of the classes loaded under
the application's classloader to be retained until the thread exits
(which is generally at JVM shutdown).

I've attached a patch that does the following:

Var.dvals is now removed when the thread bindings are popped
Var.dvals no longer has an initialValue, so checking to see if it is
set will no longer set it to an empty Frame
The outer transaction in LockingTransaction.transaction now removes
the thread local when it is finished

There is still the opportunity for memory leaks if agents or futures
are used, and the executors used for them are not shutdown when the
app is undeployed. That's a solvable problem, but should probably be
solved by the containers themselves (and/or the war generation tools)
instead of in clojure itself.

This patch has a small performance impact: its use of a try/finally
around running transactions to remove the outer transaction adds
4-6 microseconds to each transaction call on my hardware.

Providing an automated test for this patch is difficult - I've tested
it locally with repeated deployments to a container while monitoring
GC and permgen. All of clojure's tests pass with it applied.

The above is a condensation of:
https://groups.google.com/d/topic/clojure-dev/3CXDe8_9G58/discussion

I'm happy to provide whatever feedback/work is needed to get this
applied.

[CLJ-1083] Incorrect ArityException message for function names containing ->

Fri, 24 May 2013 11:35:12 -0500

user=> (defn a->b [])
#'user/a->b
user=> (a->b 1)
ArityException Wrong number of args (1) passed to: user$a clojure.lang.AFn.throwArity (AFn.java:437)

Note that the reported function name in the stack trace is "user$a", where it should be "user$a->b" (or some mangled variant thereof?)

See discussion here: https://groups.google.com/d/msg/clojure/PVNoLclhhB0/_NWqyE0cPAUJ

[CLJ-1171] Compiler macro for clojure.core/instance? disregards lexical shadows on class names

Fri, 24 May 2013 11:29:14 -0500

Summary

The compiler tries to emit jvm native instanceof expressions for direct clojure.core/instance? calls.
For that, it tries to resolve its first argument as a class name. However, it disregards lexical bindings when doing that.
This is incongruent to the default implementation in core.clj

Patches

[Stu] All three patches should be applied IMO.

0002 makes instance? respect lexical bindings
0003 makes instance?'s compiled form check arity, consistent with higher-order behavior
0001 has a minimal test for both 0002 and 0003.

Data

Test case

user=> (let [Long String] (instance? Long "abc"))
false
;; expected true as in
user=> (let [Long String] (apply instance? [Long "abc"]))
true

Culprit method

https://github.com/clojure/clojure/blob/4ccb10edbe66eae81336a4c0972050d9759b0bf7/src/jvm/clojure/lang/Compiler.java#L3578

List Discussion

https://groups.google.com/d/topic/clojure/mf25OlFRpa8/discussion

Tangent

This was discovered because the same compiler macro also omits the arity check implicit in the default definition. This could also conveniently be fixed when touching that method:

user=> (instance? String)
false
;; expected
user=> (apply instance? [String])
ArityException Wrong number of args (1) passed to: core$instance-QMARK-  clojure.lang.AFn.throwArity (AFn.java:437)

EDIT elaborated on ticket title and description; added tangent

[CLJ-1161] sources jar has bad versions.properties resource

Fri, 24 May 2013 11:13:59 -0500

Summary: patch leaves version.properties file out of sources JAR, where it causes problems for tools.

The "sources" jar (at least since Clojure 1.4 and including 1.5 RC) has a bad version.properties file in it. The resource clojure/version.properties is literally:

version=${version}

The regular Clojure jar has the correct version string in that resource.

I came across a problem when I was experimenting with the sources jar (as used by IDEs). I naively added the sources jar to my classpath, and Clojure died on start up. The bad clojure/versions.properties file was found first, which led to a parse error as the clojure version was being set.

[CLJ-1175] NPE in clojure.lang.Delay/deref

Fri, 24 May 2013 11:02:21 -0500

Summary: Delays get into a corrupt state if an exception thrown, allowing deref to behave differently on back-to-back calls. Patch causes Delay to rethrow the original exception, includes tests.

If a Delay wraps a function which throws an exception, then forcing that delay multiple times causes behavior which is, to me at least, surprising and unexpected: the first time it is forced, the expected exception is thrown; but after that it will behave as if all locals the expression refers to are nil. This can manifest in multiple ways, depending on the expression being delayed:

;; calling a local as a function causes an NPE inside clojure.lang.Delay
(let [f #(/ 1 0) d (delay (f))]
  [(try (force d) 
        (catch Exception e e))
   (try (force d)
        (catch Exception e e))])
[#<ArithmeticException java.lang.ArithmeticException: Divide by zero> 
 #<NullPointerException java.lang.NullPointerException>]

;; if nil is a valid value, this can cause subsequent forces to "succeed"
;; even though the first fails as it should
(let [x (java.util.Date.) d (delay (seq x))]
  [(try (force d) 
        (catch Exception e e))
   (try (force d)
        (catch Exception e e))])
[#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.util.Date> 
 nil]

The reason for this is that clojure.core/delay creates a ^:once function, promising to call it only once, so that the compiler can do locals-clearing on its lexical closure. However, when an exception is thrown the Delay object is left thinking it has never called the function, so when it is forced again it calls the function again, breaking its promise to the compiler and causing the function to run after its locals have been cleared.

In fact, once we realize that locals-clearing is involved, we can make the delay behave differently the first N times it is forced, instead of only the first time, by constructing an expression which throws an exception before using all of its locals:

(let [x (java.util.Date.) 
            y (Long. 1)
            d (delay (let [y (seq y)]
                       (cons (seq x) y)))]
  [(try (force d) 
        (catch Exception e e))
   (try (force d)
        (catch Exception e e))
   (try (force d)
        (catch Exception e e))])
[#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Long> 
 #<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.util.Date>
 (nil)]

I'm not sure what the right fix for this issue is: perhaps the best choice is even to leave it alone, and just document that delay's behavior is undefined if the expression throws an exception. However, I propose making the Delay remember the first exception that was thrown, and rethrow it on subsequent force attempts. This makes sense, in a way: the "result" of the expression was this exception e being thrown, and so this should happen every time. It might be preferable to have the Delay retry the expression until it succeeds, but I don't believe this is possible without abandoning locals-clearing, which would cause perfectly-valid delays to now run out of memory, holding onto no-longer-needed locals just in case the expression needs to retry at some later date.

[CLJ-1176] clojure.repl/source fails when read-eval bound to :unknown

Fri, 24 May 2013 09:42:41 -0500

clojure.repl/source is broken in Clojure 1.5.0 when *read-eval* is bound to :unknown, since source-fn reads without binding.

Reproduce:

Either set

:jvm-opts ["-Dclojure.read.eval=unknown"]

in Leiningen or eval at REPL:

(alter-var-root #'*read-eval* (constantly :unknown))

(use 'clojure.repl)
(source drop-last)

Expected:

Source of drop-last.

Actual:

RuntimeException Reading disallowed - *read-eval* bound to :unknown

[CLJ-1187] Clojure loses quoted metadata on empty literals

Fri, 24 May 2013 09:14:44 -0500

user=> (meta '^:foo [])
nil

while
user=> (meta '^:foo [1])
{:foo true}

This bug propagates to ^:const vars:
user=> (def ^:const foo ^:foo [])
#'user/foo
user=> (meta foo)
nil
user=> (meta @#'foo)
{:foo true}

[CLJ-944] compiler makes different concrete maps then the reader

Fri, 24 May 2013 09:03:46 -0500

I (Stu) agree with Nicola's assessment in the comments: the single real problem here is that the compiler's MapExpr parser emits maps differently from other map-makers, e.g. RT's factory functions.

Patch clj944-plus-tests does three things:

has the compiler emit map types consistent with the reader (like the previous "0002" patch)
adds tests
removes broken tests

Original report follows:

Hi guys, I am getting the following exception:

(.containsKey {:one 1} :one)
;=> ClassCastException clojure.lang.PersistentArrayMap cannot be cast to clojure.lang.PersistentHashMap

The map is a clojure.lang.PersistentArrayMap, which obviously has a containsKey method (https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/PersistentArrayMap.java#L95).

Casting it works fine though:

(.containsKey ^clojure.lang.PersistentArrayMap {:one 1} :one)
;=> true

The mailing list suggest that the compiler injects an incorrect cast to clojure.lang.PersistentHashMap. In this case it should probably be cast to a clojure.lang.Associative, the highest common interface having the .containsKey method.

The problem is not present in Clojure 1.2.1.

[CLJ-1121] -> and ->> have unexpected behavior when combined with unusual macros

Fri, 24 May 2013 08:48:42 -0500

My intuitive understanding of the classic threading macros is that the meaning of forms like (-> a b c) can be understood syntactically independent of the meaning of the symbols involved or the fact that the two threading macros are defined recursively. However the recursive definition breaks that expectation. After

(macroexpand-1 (macroexpand-1 '(-> a b c)))

=> (c (-> a b))

c is now in control if it is a macro, and is now seeing the argument (-> a b) rather than (b a) as would be the case if we had written (c (b a)) originally.

Admittedly I do not know of a realistic example where this is an important distinction (I noticed this when playing with a rather perverse use of ->> with macros from korma), but at the very least it means that the behavior of the threading macros isn't quite as easy to accurately explain as I thought it was.

[CLJ-873] Allow the function / to be referred to in namespaces other than clojure.core

Fri, 24 May 2013 08:39:11 -0500

The attached patch gives the programmer the option of referring to the division function in namespaces other than just clojure.core. For example,

(ns foo
(:require [cljs.core :as core]))
(apply core// '(1 2 3))

The above lines do not compile without this patch.

[CLJ-1122] Add contributing.md file to github repository (shows clear message on issues/pull request create form)

Fri, 24 May 2013 08:24:38 -0500

This adds a clear message when someone wants to create a pull request/issue and invites the user to read the contribution guidelines: see https://github.com/blog/1184-contributing-guidelines.

The same thing could be done for all the clojure/* repositories.

The content of the file is just a markdown version of http://clojure.org/contributing

Preview here: https://github.com/mpenet/clojure/blob/aef170ca5eca1b71a2eb1ef320223d1277df0e5e/CONTRIBUTING.md

[CLJ-1072] Replace old metadata reader macro syntax

Fri, 24 May 2013 07:55:10 -0500

5 files still have old metadata reader syntax hash-caret instead of just caret:

src/clj/clojure/core.clj
src/clj/clojure/gvec.clj
src/clj/clojure/java/browse_ui.clj
src/clj/clojure/java/io.clj
src/clj/clojure/repl.clj

[CLJ-896] Make browse-url aware of xdg-open

Fri, 24 May 2013 07:55:10 -0500

clojure.java.browse/browse-url tests to see if it's running on Mac OS to fall back to "/usr/bin/open" in order
to open a URI. On most other systems it'll just falls through to open-url-in-swing instead. The attached patch
tests to see if freedesktop.org's "xdg-open" is present in the users path. This way browse-url will launch the
program associated with the URI, in my case chromium.

[CLJ-863] interleave should accept 1 or 0 arguments

Fri, 24 May 2013 07:55:10 -0500

interleave should handle 0 and 1 arguments in the same way that concat does (i.e., 0 args --> empty seq, 1 args --> identity).

[CLJ-783] clojure.inspector/inspect-tree doesn't work on sets --patch in the description by Jason Wolfe

Fri, 24 May 2013 07:55:10 -0500

As reported by Jason Wolfe on March 19, 2009 in the clojure group:

clojure.inspector/inspect-tree doesn't work on sets; patch attached
http://groups.google.com/group/clojure/browse_thread/thread/97bcad115fcfaf5a/95e61c423c61cfa8?lnk=gst&q=inspector+set#95e61c423c61cfa8

I was debugging with inspect-tree and noticed that it errors when it
encounters a set (it thinks it's not atomic, but then nth produces an
UnsupportedOperationException).

I made a small patch (below) that makes inspect-tree work on
java.util.Sets, and also anything else that implements
clojure.lang.Seqable. If this is of interest, please let me know and
I can create an issue.

Cheers,
Jason

Index: src/clj/clojure/inspector.clj
===================================================================
— src/clj/clojure/inspector.clj (revision 1335)
+++ src/clj/clojure/inspector.clj (working copy)
@@ -20,8 +20,10 @@
(defn collection-tag [x]
(cond
(instance? java.util.Map$Entry x) :entry

(instance? java.util.Map x) :map
+ (instance? java.util.Map x) :seqable
+ (instance? java.util.Set x) :seqable
(sequential? x) :seq
+ (instance? clojure.lang.Seqable x) :seqable
:else :atom))

(defmulti is-leaf collection-tag)
@@ -42,11 +44,15 @@
(defmethod get-child-count :entry [e]
(count (val e)))

-(defmethod is-leaf :map [m]
+(defmethod is-leaf :seqable [parent]
false)
-(defmethod get-child :map [m index]

(nth (seq m) index))
+(defmethod get-child :seqable [parent index]
+ (nth (seq parent) index))
+(defmethod get-child-count :seqable [parent]
+ (count (seq parent)))

(defn tree-model [data]
(proxy [TreeModel] []
(getRoot [] data)

[CLJ-1164] typos in instant.clj

Fri, 24 May 2013 07:55:08 -0500

There are a few typographical mistakes in instant.clj.

[CLJ-1143] Minor correction to doc string of ns macro

Fri, 24 May 2013 07:55:08 -0500

The doc string of ns says "If :refer-clojure is not used, a default (refer 'clojure) is used." 'clojure should be replaced with 'clojure.core

Clojure group thread: https://groups.google.com/forum/?fromgroups=#!topic/clojure/rDjZodxOMh8

[CLJ-1101] default-data-reader-fn should be set!-able in REPL

Fri, 24 May 2013 07:55:08 -0500

In ~~CLJ-927~~, Nicola Mometto pointed out that *default-data-reader-fn* should be set!-able. The fix needs to be added to clojure.main/with-bindings.

[CLJ-1099] better error message when passing non-seq to seq

Fri, 24 May 2013 07:55:08 -0500

Design discussion here.

This patch improves Clojure's error message for a single common error: passing a non-seq where a seq is neede. More importantly, it is intended as a prototype for other similar improvements in the future.

Error message before:

(cons 1 2)
=> IllegalArgumentException Don't know how to create ISeq from: java.lang.Long

Error message after:

user=> (cons 1 2)
ExceptionInfo Don't know how to create ISeq from: java.lang.Long
user=> (ex-data *e)
{:instance 2}

[CLJ-908] Functions with metadata print poorly

Fri, 24 May 2013 07:55:08 -0500

1.3 removed the metadata slot on most functions, and made .withMeta return a new wrapping function that provides metadata. This changes the way functions with metadata print: instead of #<user$eval595$fn_596 user$eval595$fn_596@3d48ff04> we now see #< clojure.lang.AFunction$1@581de498>. I might argue that we should "lie" and print the class of the original wrapped function since it's more useful than AFunction$1, but that's debatable. The two things I propose changing are:

When *print-meta* is true, we should print the metadata map for functions. That nothing prints implies there is no metadata, which can make it difficult to track down bugs related to metadata on functions.
Remove the errant space at the front of the printed representation of functions with meta, changing #< clojure.lang.AFunction$1@581de498> to #<clojure.lang.AFunction$1@581de498>. The cause of this issue is that .getSimpleName on an object with an anonymous class returns "", and we print that followed by a space and its .toString. My fix is to omit the extra space if the class has no simple name; this would cause instances of other anonymous (non-function) classes to print more nicely as well.

If it would be desirable to print the class of the original "wrapped" function, then I can easily add another patch for that.

[CLJ-1018] range's behavior is inconsistent

Fri, 24 May 2013 07:34:58 -0500

Problem statement: The current behavior of range is inconsistent. (range 0 9 0) has always produced (). (range 0 9 -1) has always produced (). (range 9 0 1) has always produced (). However, (range 9 0 0) produces (9 9 9 9 ...), and (range 0 0 0) produces '(0 0 0 0 ...)

Proposal: Make the behavior of range consistent when using a step of 0 to make it produce an empty list.

Please see attached code and patch.

[CLJ-1078] Added queue, queue* and queue? to clojure.core

Thu, 23 May 2013 20:54:15 -0500

This patch adds functions for PersistentQueue. queue, queue? and queue* match the list functions of the same naming conventions. Patches include updates to tests.

[CLJ-1210] error message for (clojure.java.io/reader nil) — consistency for use with io/resource

Thu, 23 May 2013 17:59:08 -0500

This seems to a common idiom:

(clojure.java.io/reader (clojure.java.io/resource "myfile"))

When a file is available these are the behaviors:

=> (clojure.java.io/reader "resources/myfile")
#<BufferedReader java.io.BufferedReader@1f291df0>

=> (clojure.java.io/resource "myfile")
#<URL file:/project/resources/myfile>

=> (clojure.java.io/reader (clojure.java.io/resource "myfile"))
#<BufferedReader java.io.BufferedReader@1db04f7c>

If the file (resource) is unavailable:

=> (clojure.java.io/reader "resources/nofile")
FileNotFoundException resources/nofile (No such file or directory) java.io.FileInputStream.open (FileInputStream.java:-2)

=> (clojure.java.io/resource "nofile")
nil

=> (clojure.java.io/reader (clojure.java.io/resource "nofile"))
IllegalArgumentException No implementation of method: :make-reader of protocol: #'clojure.java.io/IOFactory found for class: nil clojure.core/-cache-protocol-fn (core_deftype.clj:541)

The main enhancement request is to have a better error message from `(clojure.java.io/reader nil)`. I'm not sure if io/resource should return something like 'resource "nofile" not found' or if io/reader could add a more helpful suggestion.

[CLJ-1201] There should also be writing in clojure.edn

Thu, 23 May 2013 17:56:23 -0500

In clojure.edn I see only "read" and "read-string".

For symmetry I expect "write" and "write-string" to be nearby. At first it could be just alias for "pr" and "pr-str", but in furure they may limited version of "pr" which only produces valid input for clojure.edn/read.

[CLJ-999] Wrong link in gh-pages index (api-index.html)

Mon, 20 May 2013 16:24:12 -0500

The api-index.html includes wrong links for the following:

All entries for all listed as part of clojure.test.tap
All entries for all listed as part of clojure.test.junit
All entries for all listed as part of clojure.core.protocols

The links point to pages that do not exist. The problem is that the documentation for those entries is on a "parent" page, for example, the link clojure.core.protocols-api.html#clojure.core.protocols/internal-reduce should have been clojure.core-api.html#clojure.core.protocols/internal-reduce

Not a huge bug for me, but you might want to get it fixed.

And please give my huge thanks to whoever is in charge of the documentation, I'm the developer behind Dash, a Mac OS X documentation browser, and I was in the process of creating a documentation set for Clojure, and because you guys have an index, you made my work 1000 times easier.

[CLJ-1147] Threading macro (->) does not permit inline function declarations

Sun, 19 May 2013 22:29:46 -0500

(-> [1 2 3] (fn [args] apply + args))

CompilerException java.lang.Exception: Unsupported binding form: 1, compiling:(NO_SOURCE_PATH:1:13)

The expression is expanded to:

(fn [1 2 3] [args] apply + args)

If this is intended behaviour then at the least the compiler error message is confusing. It would be preferable if the -> macro checked for (fn..) before treating a form as a sequence and injecting the argument.

[CLJ-1183] java interop - cannot call a final method on non-public superclass

Sat, 18 May 2013 19:22:33 -0500

when trying to call a method on a concrete class that is defined as final on its super class that is not public, the runtime throws:

"java.lang.IllegalArgumentException: Can't call public method of non-public class"

even when fully annotated, Reflection is still used and the call fails.

you can read the full description here https://groups.google.com/d/msg/clojure/p2tBMT-BIYc/mDQB8cSponMJ

I included a sample project that demonstrate the problem

[CLJ-1131] Importing a non-existent class causes an exception that does not fully identify the source file

Fri, 17 May 2013 15:56:48 -0500

I'm in the process of stripping out some OSGi support, and I missed one import.

The exception identifies "init.clj", but I'd prefer to see the full path there, as I have a few different "init.clj" files in my overall project.

:core-services:compileClojure
Reflection warning, com/annadaletech/nexus/services/registry.clj:37 - call to unregisterAll can't be resolved.
Reflection warning, com/annadaletech/nexus/services/registry.clj:131 - call to getConfiguration can't be resolved.
Reflection warning, com/annadaletech/nexus/services/registry.clj:150 - call to getConfiguration can't be resolved.
Exception in thread "main" java.lang.ClassNotFoundException: org.osgi.framework.ServiceRegistration, compiling:(init.clj:1)
	at clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3387)
	at clojure.lang.Compiler.compile1(Compiler.java:7035)
	at clojure.lang.Compiler.compile1(Compiler.java:7025)
	at clojure.lang.Compiler.compile(Compiler.java:7097)
	at clojure.lang.RT.compile(RT.java:387)
	at clojure.lang.RT.load(RT.java:427)
	at clojure.lang.RT.load(RT.java:400)
	at clojure.core$load$fn__4890.invoke(core.clj:5415)
	at clojure.core$load.doInvoke(core.clj:5414)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invoke(core.clj:5227)
	at clojure.core$compile$fn__4895.invoke(core.clj:5426)
	at clojure.core$compile.invoke(core.clj:5425)
	at clojuresque.tasks.compile$main$fn__64.invoke(compile.clj:23)
	at clojuresque.cli$with_command_line_STAR_.invoke(cli.clj:92)
	at clojuresque.tasks.compile$main.doInvoke(compile.clj:6)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:601)
	at clojure.lang.Var.invoke(Var.java:419)
	at clojuresque.Driver.main(Driver.java:39)
Caused by: java.lang.ClassNotFoundException: org.osgi.framework.ServiceRegistration

[CLJ-1173] One-arg protocol functions whose name begins in a dash generates a call to a wrong field in the emitted code

Fri, 17 May 2013 13:36:40 -0500

(defprotocol P (-foo [this]))

This code generates a reflective call to a non-existing foo field instead of the correct -foo method.

I was told by Christophe Grand that changing the line 557 in core_deftype.clj from:

(. ~(with-meta target {:tag on-interface}) ~(or on-method method) ~@(rest gargs))

(. ~(with-meta target {:tag on-interface}) (~(or on-method method) ~@(rest gargs)))

is a quick fix. However I don't know too much about the compilation specifics of . to judge whether this is the correct fix.

Issue reproduction:

Clojure
user=> (set! *warn-on-reflection* true)
true
user=> (defprotocol P (-foo [this]))
P
Reflection warning, REPL:4 - reference to field foo can't be resolved.

[CLJ-1117] Partition does not follow docs

Fri, 17 May 2013 10:14:56 -0500

The doc for partition states "In case there are not enough padding elements, return a partition with less than n items."

However, the behavior of this function is as follows:

user=> (partition 3 (range 10))
((0 1 2) (3 4 5) (6 7 8))
user=> (partition 4 (range 10))
((0 1 2 3) (4 5 6 7))
user=> (partition 5 (range 10))
((0 1 2 3 4) (5 6 7 8 9))

Either the doc should be updated to make it clear that not providing a pad will mean that items are dropped, or the functionality of partition should be fixed to the following:

user=> (partition 3 (range 10))
((0 1 2) (3 4 5) (6 7 8) (9))

[CLJ-1209] Teach clojure.test reporting about ex-info/ex-data

Sat, 11 May 2013 04:12:35 -0500

When clojure.test/deftest does error reports on unexpected exceptions it currently ignores ExceptionInfo and the valuable ex-data it carries. So this patch simple prints this data, it might be helpful to pprint or format it in another way but this was good enough for me.

See example from my tests: https://gist.github.com/thheller/5559391

[CLJ-1207] Importing a class that does not exist fails to report the name of the class that did not exist

Fri, 10 May 2013 16:51:24 -0500

Pop quiz: What Java class is missing from the classpath?

java.lang.NoClassDefFoundError: Could not initialize class com.annadaletech.nexus.util.logging__init
 at java.lang.Class.forName0 (Class.java:-2)
    java.lang.Class.forName (Class.java:264)
    clojure.lang.RT.loadClassForName (RT.java:2098)
    clojure.lang.RT.load (RT.java:430)
    clojure.lang.RT.load (RT.java:411)
    clojure.core$load$fn__5018.invoke (core.clj:5530)
    clojure.core$load.doInvoke (core.clj:5529)
    clojure.lang.RestFn.invoke (RestFn.java:408)
    clojure.core$load_one.invoke (core.clj:5336)
    clojure.core$load_lib$fn__4967.invoke (core.clj:5375)
    clojure.core$load_lib.doInvoke (core.clj:5374)
    clojure.lang.RestFn.applyTo (RestFn.java:142)
    clojure.core$apply.invoke (core.clj:619)
    clojure.core$load_libs.doInvoke (core.clj:5413)
    clojure.lang.RestFn.applyTo (RestFn.java:137)
    clojure.core$apply.invoke (core.clj:619)
    clojure.core$require.doInvoke (core.clj:5496)
    clojure.lang.RestFn.invoke (RestFn.java:512)
    novate.console.app$eval1736$loading__4910__auto____1737.invoke (app.clj:1)
    novate.console.app$eval1736.invoke (app.clj:1)
    clojure.lang.Compiler.eval (Compiler.java:6619)
    clojure.lang.Compiler.eval (Compiler.java:6608)
    clojure.lang.Compiler.load (Compiler.java:7064)
    user$eval1732.invoke (NO_SOURCE_FILE:1)
    clojure.lang.Compiler.eval (Compiler.java:6619)
    clojure.lang.Compiler.eval (Compiler.java:6582)
    clojure.core$eval.invoke (core.clj:2852)
    clojure.main$repl$read_eval_print__6588$fn__6591.invoke (main.clj:259)
    clojure.main$repl$read_eval_print__6588.invoke (main.clj:259)
    clojure.main$repl$fn__6597.invoke (main.clj:277)
    clojure.main$repl.doInvoke (main.clj:277)
    clojure.lang.RestFn.invoke (RestFn.java:1096)
    clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__584.invoke (interruptible_eval.clj:56)
    clojure.lang.AFn.applyToHelper (AFn.java:159)
    clojure.lang.AFn.applyTo (AFn.java:151)
    clojure.core$apply.invoke (core.clj:617)
    clojure.core$with_bindings_STAR_.doInvoke (core.clj:1788)
    clojure.lang.RestFn.invoke (RestFn.java:425)
    clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invoke (interruptible_eval.clj:41)
    clojure.tools.nrepl.middleware.interruptible_eval$interruptible_eval$fn__625$fn__628.invoke (interruptible_eval.clj:171)
    clojure.core$comp$fn__4154.invoke (core.clj:2330)
    clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__618.invoke (interruptible_eval.clj:138)
    clojure.lang.AFn.run (AFn.java:24)
    java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1110)
    java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:603)
    java.lang.Thread.run (Thread.java:722)

If you guess "com.annadaletech.nexus.util.logging__init" you are wrong!

Wait, I'll give you a hint:

(ns com.annadaletech.nexus.util.logging
  (:use [clojure.string :only [trim-newline]]
        [clojure.pprint :only [code-dispatch pprint with-pprint-dispatch *print-right-margin*]])
  (:import [java.io StringWriter]
           [org.slf4j MDC MarkerFactory Marker LoggerFactory]
           [java.util.concurrent.locks ReentrantLock]))

Oh, sorry, did that not help?

The correct answer is "org.slf4j.MDC".

Having that information in the stack trace would have saved me nearly an hour. I think it is worth the effort to get that reported correctly.

[CLJ-1202] protocol fns with dashes may get compiled into property access when used higher order

Fri, 10 May 2013 15:19:29 -0500

user=> (defprotocol Foo (-foo [x]))
Foo
user=> (deftype Bar [] Foo (-foo [_] :baz))
user.Bar
user=> (map -foo [(Bar.)])
IllegalArgumentException No matching field found: foo for class user.Bar  
clojure.lang.Reflector.getInstanceField (Reflector.java:271)

I would have expected to see (:baz). The full stack is:

IllegalArgumentException No matching field found: foo for class user.Bar
	clojure.lang.Reflector.getInstanceField (Reflector.java:271)
	clojure.lang.Reflector.invokeNoArgInstanceMember (Reflector.java:300)
	user/eval79/fn--80/G--71--82 (NO_SOURCE_FILE:11)
	user/eval79/fn--80/G--70--85 (NO_SOURCE_FILE:11)
	clojure.core/map/fn--4207 (core.clj:2485)
	clojure.lang.LazySeq.sval (LazySeq.java:42)
	clojure.lang.LazySeq.seq (LazySeq.java:60)
	clojure.lang.RT.seq (RT.java:484)
	clojure.core/seq (core.clj:133)
	clojure.core/print-sequential (core_print.clj:46)
	clojure.core/fn--5406 (core_print.clj:143)
	clojure.lang.MultiFn.invoke (MultiFn.java:231)
nil

I suspect this is somehow related to the property access changes to make Clojure/ClojureScript compatible. I was in fact prepping core.logic for a unified code base and was adopting the ClojureScript protocol naming convention when I encountered this issue.

~~CLJ-872~~ added dash property support to Clojure.

[CLJ-866] Provide a clojure.test function to run a single test case with fixtures

Sat, 4 May 2013 09:36:20 -0500

At present, clojure.test test cases are functions and can be invoked directly. However, in the case that the test relies on fixtures, this does not work. Please provide a function that can run a single test case with all fixtures applied.

[CLJ-766] Implicit casting behaviour of into-array differs from -array

Fri, 3 May 2013 20:46:29 -0500

Current patch: byte-short-array-ctors.diff

The behavior of byte-array and short-array is inconsistent with the other <type>-array functions and with the into-array function when invoked with types other than byte or short. All of the other cases upcast to Number, then extract the primitive value, allowing this operation to succeed (assuming the value is in range). byte-array and short-array throw a ClassCastException.

Example:

base64v3a=> (into-array Byte/TYPE [1 2 3 4])  ;; int to byte ok
#<byte[] [B@5ee04fd>
base64v3a=> (byte-array [1 2 3 4])  ;; int to byte NOT ok!! 
ClassCastException java.lang.Long cannot be cast to java.lang.Byte
  clojure.lang.Numbers.byte_array (Numbers.java:1418)
base64v3a=> (long-array [1 2 3 4])  ;; int to long ok
#<long[] [J@3f9f4d1d>

into-array (via RT.seqToTypedArray) and the other <type>-array functions all upcast to Number (via Numbers.<type>_array}}), then obtain the proper primitive value. Numbers.byte-array and Numbers.short-array do casts directly to Byte and Short (yielding the ClassCastException).

The attached patch makes the Byte and Short cases match the other types and the into-array behavior. Tests are included. The submitter is a contributor.

[CLJ-1208] Namespace is not loaded on defrecord class init

Fri, 3 May 2013 17:21:54 -0500

As a user of Clojure interop from Java, I want defrecords (and deftypes?) to load their namespaces upon class initialization so that I can simply construct and use AOT'd record classes without manually requiring their namespaces first.

Calling the defrecord's constructor may or may not result in "Attempting to call unbound fn" exceptions, depending on what code has already been run.

This issue has been raised several times over the years, but I could not find an existing ticket for it:

[CLJ-428] subseq, rsubseq enhancements to support priority maps?

Wed, 1 May 2013 02:44:36 -0500

See dev thread at http://groups.google.com/group/clojure-dev/browse_thread/thread/fdb000cae4f66a95.

Note: subseq currently returns () instead of nil in some situations. If the rest of this idea dies we might still want to fix that.

[CLJ-1203] Fallback to hash-based comparison for non-Comparables in Util.compare()

Mon, 29 Apr 2013 02:30:08 -0500

I oftentimes use sorted collections, and my comparator functions usually look like that:

(fn [a b]
  (let [x (compare-according-to-my-use-case a b)]
    (if (zero? x)
       (compare a b)
       x)))

That is, I define the sorting order depending on the requirements of my use-case, and if that doesn't suffice to make a distinction, I simply fall back to the standard `compare` function in order to get a stable ordering anyhow. I think that's a widely used idiom, e.g., also used in "Clojure Programming" (for example page 109).

The problem with this approach is that several data structures don't implement Comparable, and thus aren't applicable to `compare` (you'll get a ClassCastException). Examples are maps, records, deftypes, and sequences.

The patch I'm going to attach extends `Util.compare()` with a fallback clause that performs a `hasheq()`-based comparison. This results in a meaningless but at least stable sorting order which suffices for use-cases like the one shown above.

[CLJ-1206] 'eval' of closures or fns with runtime metadata within a call expr yields "No matching ctor found" exceptions

Sun, 28 Apr 2013 18:27:49 -0500

I ran into some issues with 'eval' when writing compilation strategies for Graph. It seems these may have been known for some time [1], but I couldn't find a ticket for them, so here we are.

Clojure docs [2] say "If the operator is not a special form or macro, the call is considered a function call. Both the operator and the operands (if any) are evaluated, from left to right," and "Any object other than those discussed above will evaluate to itself." While bare fns do seem to evaluate to themselves in all cases, when in a call expression, the evaluation of the operator fails on fn objects that are closures or have run-time metadata applied:

;; raw non-closures are fine
user> (eval (fn [x] (inc x)))
#<user$eval30559$fn_30560 user$eval30559$fn_30560@354ee11c>

;; raw closures are fine
user> (eval (let [y 1] (fn [x] (+ x y))))
#<user$eval30511$fn_30512 user$eval30511$fn_30512@3bac3a34>

;; non-closures in exprs are fine
user> (eval `(~(fn [x] (inc x)) 1))
2

;; but closures in exprs cause an error
user> (eval `(~(let [y 1] (fn [x] (+ x y))) 1))
IllegalArgumentException No matching ctor found for class user$eval30535$fn__30536 clojure.lang.Reflector.invokeConstructor (Reflector.java:163)

;; as do fns with metadata in exprs
user> (eval `(~(with-meta (fn [x] (inc x)) {:x 1}) 1))
IllegalArgumentException No matching ctor found for class clojure.lang.AFunction$1 clojure.lang.Reflector.invokeConstructor (Reflector.java:163)

[1] http://stackoverflow.com/a/11287181
[2] http://clojure.org/evaluation

[CLJ-1118] inconsistent numeric comparison semantics between BigDecimal and other Numerics

Thu, 25 Apr 2013 19:58:50 -0500

user> clojure-version
{:major 1, :minor 5, :incremental 0, :qualifier "beta1"}
user> (== 2.0 2.0M)
true
user> (== 2 2.0M)
false <-- this one is not like the others
user> (== 2 2.0)
true
user> (== 2N 2.0)
true
user> (== 2 (double 2.0M))
true

It's not clear if this is a bug or an enhancement request, Should BigDecimal's be special in comparason to their smaller equivalents?

[CLJ-1204] hash is inconsistent with = for many BigInteger values

Thu, 25 Apr 2013 18:42:40 -0500

The function hash is documented to be consistent with =. For many BigInteger values, hash is inconsistent with =. This leads to incorrect behavior for data structures like hash maps that use hash.

user> (apply = [-1 -1N (biginteger -1)])
true
user> (map hash [-1 -1N (biginteger -1)])
(0 0 -1)

;; Incorrect return value with multiple keys = to each other
user> (assoc (hash-map -1N :should-be-replaced) (biginteger -1) :new-val)
{-1N :should-be-replaced, -1 :new-val}

;; array-map gives correct value, since it uses =, not hash
user> (assoc (array-map -1N :should-be-replaced) (biginteger -1) :new-val)
{-1N :new-val}

[CLJ-1205] Update Maven build for Nexus 2.4

Mon, 22 Apr 2013 20:29:15 -0500

These additions to the build configuration are necessary to support changes to the Sonatype Nexus server at oss.sonatype.org, which we use to promote our build artifacts into the Maven Central Repository.

See Sonatype's announcement at https://groups.google.com/d/msg/clojure-dev/lBpfII2u6vM/LQvr_rO5UGgJ

[CLJ-1200] RestFn & ArraySeq performance

Thu, 18 Apr 2013 16:03:25 -0500

I was profiling one of my projects and noticed a hotspot inside functions using rest arguments.

Most overloads of RestFn.invoke will construct an ArraySeq object. The ArraySeq constructor calls java.lang.Class.getComponentType, which seems to be pretty slow. The array's component type is cached in a field on the ArraySeq object for the sole purpose of passing it to Reflector.prepRet. I'm not entirely sure of the total utility of prepRet, but it's clearly a no-op when passed Object.class, such as the case with the non-specialized base class of ArraySeq: the component type of object[] is Object.class.

The attached patch eliminates the component type field from ArraySeq and passes Object.class to prepRet directly. It may be possible to eliminate calls to prepRet all together, but I'll assume that's a different ticket. With this patch, ArraySeq initialization no longer shows up as a hotspot when profiling.

Before the patch:

user=> (dotimes [n 10] (time (dotimes [i 5000000] ((fn [& args]) 1 2 3 4))))
"Elapsed time: 874.742 msecs"
"Elapsed time: 900.277 msecs"
"Elapsed time: 911.164 msecs"
"Elapsed time: 872.132 msecs"
"Elapsed time: 885.495 msecs"
"Elapsed time: 897.537 msecs"
"Elapsed time: 879.691 msecs"
"Elapsed time: 888.52 msecs"
"Elapsed time: 871.556 msecs"
"Elapsed time: 1088.682 msecs"

After the patch:

user=> (dotimes [n 10] (time (dotimes [i 5000000] ((fn [& args]) 1 2 3 4))))
"Elapsed time: 628.144 msecs"
"Elapsed time: 634.163 msecs"
"Elapsed time: 617.397 msecs"
"Elapsed time: 622.714 msecs"
"Elapsed time: 646.743 msecs"
"Elapsed time: 648.708 msecs"
"Elapsed time: 629.223 msecs"
"Elapsed time: 638.058 msecs"
"Elapsed time: 725.473 msecs"
"Elapsed time: 636.909 msecs"

That's about a 30% reduction in execution time.

Granted it only represents a change of 52 nanoseconds per RestFn invoke (181 ns to 129 ns), but this actually was a pretty decent win for a library that makes makes almost exclusively variadic function calls in a tight loop.

[CLJ-889] Specifically allow '.' inside keywords

Mon, 15 Apr 2013 05:56:25 -0500

The documentation for keywords (on page http://clojure.org/reader) specifically states that '.' is not allowed as part of a keyword name; however '.' is specifically useful. For example, several web frameworks for Clojure use keywords to represent HTML elements, using CSS selector syntax (i.e., :div.important is equivalent to <div class='important'>).

In any case, the use of '.' is not checked by the reader and it is generally useful.

I would like to see '.' officially allowed (in the documentation). Further, I'd like to see additional details about which punctuation characters are allowed (my own web framework uses '&', '?' and '>' inside keywords for various purposes ... again, current reader implementation does not forbid this, but if a future reader will reject it, I'd like to know now).

[CLJ-1182] Regexp are never equal

Sat, 13 Apr 2013 21:13:52 -0500

The following (= #"asd" #"asd") will return false in CLJ, even if they are the same.

Consequently, everything with a regexp in it (lists, vectors, maps...) will never be equal.

It seems to have been fixed for CLJS, but not for CLJ.
https://github.com/clojure/clojurescript/commit/e35c3a57472fa62ae41591418a73794dc8ac6dde

[CLJ-1199] Record values are not 'eval'uated, unlike values of PersistentMap:

Sat, 13 Apr 2013 00:29:58 -0500

I'm not sure if this is by design, but it caught me off guard.

user> (defrecord A [x])
user.A

user> (eval (hash-map :x `long))
{:x #<core$long clojure.core$long@5de54eb7>}
user> (eval (->A `long))
#user.A{:x clojure.core/long}
user> (eval (map->A (hash-map :x `long)))
#user.A{:x clojure.core/long}

and in case it matters, here's a simplified version of the real use case where this came up, with no eval – just a macro:

user> (defmacro munge-meta1 [x] (assoc x :schema (->A (:schema (meta x)))))
#'user/munge-meta1
user> (munge-meta1 ^{:schema long} {})
{:schema #user.A{:x long}}

user> (defmacro munge-meta2 [x] (assoc x :schema (hash-map :x (:schema (meta x)))))
#'user/munge-meta2
user> (munge-meta2 ^{:schema long} {})
{:schema {:x #<core$long clojure.core$long@5de54eb7>}}

This seems to be fixed by moving the record creation post-evaluation, so it's not a big deal, just surprising (plus I haven't yet convinced myself that this will always work if the user's schema itself contains record-creating forms, although it seems to work OK):

user> (defmacro munge-meta1 [x] (assoc x :schema `(->A ~(:schema (meta x)))))
#'user/munge-meta1
user> (munge-meta1 ^{:schema long} {})
{:schema #user.A{:x #<core$long clojure.core$long@5de54eb7>}}

I brought this up on the mailing list here:

https://groups.google.com/forum/?fromgroups=#!topic/clojure-dev/UgD35E1RQTo

[CLJ-1198] Apply metadata to primitive fns causes them to lose their primitive-ness

Sat, 13 Apr 2013 00:27:45 -0500

user> (def f (fn [^long x] x))
#'user/f
user> (.invokePrim (with-meta f {}) 1)
IllegalArgumentException No matching method found: invokePrim for class clojure.lang.AFunction$1 clojure.lang.Reflector.invokeMatchingMethod (Reflector.java:53)
user> (contains? (ancestors (class f)) clojure.lang.IFn$LO)
true
user> (contains? (ancestors (class (with-meta f {}))) clojure.lang.IFn$LO)
false

We're working on libraries that use metadata on functions to track information about their arguments (schemata, etc), and this currently blocks us from fully supporting primitive fns.

[CLJ-1188] Public Java API

Fri, 12 Apr 2013 13:51:46 -0500

Problem: Java consumers need an API into Clojure that does not drag in a ton of concrete implementation detail.

Solution: Very small API class that allows looking up Vars (returning IFn), and reading data (as edn). Uses Clojure logic where possible, e.g. Var.intern.

Current patch: ~~CLJ-1188~~-via-var-intern.patch

Also considered:

wrapper class (inconvenient for users, wrappers anathema in Clojure)
common superinterface for IFn and Deref (unnecessary, might bloat vtable)

[CLJ-196] file returns "NO_SOURCE_PATH", but the doc says it should be nil

Fri, 12 Apr 2013 10:05:40 -0500

According to http://clojure.org/api, *file* should return nil in the repl, but it returns "NO_SOURCE_PATH".

This has been true for a long time. Latest patch changes only the docstring of *file* to accurately reflect current behavior.

[CLJ-124] GC Issue 120: Determine mechanism for controlling automatic shutdown of Agents, with a default policy and mechanism for changing that policy as needed

Fri, 12 Apr 2013 09:52:24 -0500

Reported by cemer...@snowtide.com, Jun 01, 2009

There has been intermittent chatter over the past months from a couple of
people on the group (e.g.
http://groups.google.com/group/clojure/browse_thread/thread/409054e3542adc1f)
and in #clojure about some clojure scripts hanging, either for a constant
time (usually reported as a minute or so with no CPU util) or seemingly
forever (or until someone kills the process).

I just hit a similar situation in our compilation process, which invokes
clojure.lang.Compile from ant.  The build process for this particular
project had taken 15 second or so, but after adding a couple of pmap calls,
that build time jumped to ~1:15, with roughly zero CPU utilization over the
course of that last minute.

Adding a call to Agent.shutdown() in the finally block in
clojure.lang.Compile/main resolved the problem; a patch including this
change is attached.  I wouldn't suspect anyone would have any issues with
such a change.

-----
In general, it doesn't seem like everyone should keep tripping over this
problem in different directions.  It's a very difficult thing to debug if
you're not attuned to how clojure's concurrency primitives work under the
hood, and I would bet that newer users would be particularly affected.

After discussion in #clojure, rhickey suggested adding a
*auto-shutdown-agents* var, which:

- if true when exiting one of the main entry points (clojure.main, or the
legacy script/repl entry points), Agent.shutdown() would be called,
allowing for the clean exit of the application

- would be bound by default to true

- could be easily set to false for anyone with an advanced use-case that
requires agents to remain active after the main thread of the application
exits.

This would obviously not help anyone initializing clojure from a different
entry point, but this may represent the best compromise between
least-surprise and maximal functionality for advanced users.

------

In addition to the above, it perhaps might be worthwhile to change the
keepalive values used to create the Threadpools used by c.l.Actor's
Executors.  Currently, Actor uses a default thread pool executor, which
results in a 60s keepalive.  Lowering this to something much smaller (1s?
5s?) would additionally minimize the impact of Agent's threadpools on Java
applications that embed clojure directly (and would therefore not benefit
from *auto-shutdown-agents* as currently conceived, leading to puzzling
'hanging' behaviour).  I'm not in a position to determine what impact this
would have on performance due to thread churn, but it would at least
minimize what would be perceived as undesirable behaviour by users that are
less familiar with the implementation details of Agent and code that
depends on it.

Comment 1  by cemer...@snowtide.com, Jun 01, 2009

Just FYI, I'd be happy to provide patches for either of the suggestions mentioned
above...

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

Fri, 12 Apr 2013 09:42:02 -0500

Evaluating a persistent collection for which the function 'first' returns the symbol 'do' leads to that collection being treated as the do special form, even though it may be a vector or even a set. IMHO, the expected result would be to report that 'do' cannot be resolved. For the cause, see the if condition on line 6604 of Compiler.java in clojure-1.5.1.

E.g.:
[do 1 2]
;=> 2

#{"hello" "goodbye" do}
;=> "hello"
; Wat?

[CLJ-1058] StackOverflowError on exception in reducef for PersistentHashMap fold

Fri, 12 Apr 2013 09:42:02 -0500

If reducef throws an exception, the PHM fold code can descend into an infinite loop, causing a stack overflow which masks the problem. This situation is commented "aargh" in PersistentHashMap.java line 444 (as of 412a51d).

To reproduce:

user> (require '[clojure.core.reducers :as r])
nil
user> (r/fold (fn ([]) ([ret k v] (+ 3 "foo") ret)) (into {} (map (juxt identity identity) (range 10000))))
;; boom

This results in a stack like: https://raw.github.com/gist/3bab917287a7fd635a84/f38bfe3e270556e467f3fc02062af7ea10781390/gistfile1.txt

[CLJ-420] Some compiler exceptions erroneously using REPL line numbers.

Fri, 12 Apr 2013 09:42:02 -0500

Certain kinds of errors in loaded source files are coming back tagged with the correct source file, but what seems to be the REPL line number.

http://groups.google.com/group/clojure/browse_frm/thread/beb36e7228eabd69/a7ef16dcc45834bc?hl=en#a7ef16dcc45834bc

jawolfe@[~/Projects/testproj]: cat > src/test.clj

bla
jawolfe@[~/Projects/testproj]: cat > src/test2.clj

(bla)
jawolfe@[~/Projects/testproj]: lein repl
user=> (require 'test)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test.clj:1)
user=> (require 'test)a
java.lang.Exception: Unable to resolve symbol: bla in this context
(test.clj:2)
user=> (require 'test)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test.clj:3)
user=> (require 'test2)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test2.clj:2)
user=> (require 'test2)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test2.clj:2)
user=> (require 'test2)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test2.clj:2)
user=> (require 'test)
java.lang.Exception: Unable to resolve symbol: bla in this context
(test.clj:7)
user=>

[CLJ-1105] defrecord classes implement IPersistentCollection but not .empty, clojure.walk assumes collections support empty

Fri, 12 Apr 2013 09:42:00 -0500

Using clojure.walk functions fails surprisingly for data containing records defined with defrecord:

user=> (defrecord Foo [x])
user.Foo
user=> (def f (Foo. :x))
#'user/f
user=> (use 'clojure.walk)
nil
user=> (postwalk identity {:foo f})
UnsupportedOperationException Can't create empty: user.Foo user.Foo (NO_SOURCE_FILE:1)

This seems to be because clojure.walk/walk guards a call to (empty form) with a (coll? form) check. The check succeeds because records implement IPersistentCollection, but (empty form) throws an exception. This looks to me like a bug in clojure.walk (it should check records separately and either treat them as atomic or implement a way of walking through them) but perhaps it is a sign of some unclarity in the contract of collections.

[CLJ-787] transient blows up when passed a vector created by subvec

Fri, 12 Apr 2013 09:42:00 -0500

Subvectors created with subvec from a PersistentVector cannot be made transient:

user=> (transient (subvec [1 2 3 4] 2))
ClassCastException clojure.lang.APersistentVector$SubVector cannot be cast to clojure.lang.IEditableCollection  clojure.core/transient (core.clj:2864)

[CLJ-701] Compiler loses 'loop's return type in some cases

Fri, 12 Apr 2013 09:42:00 -0500

(set! *warn-on-reflection* true)
(fn [] (loop [b 0] (recur (loop [a 1] a))))

Generates the following warnings:

recur arg for primitive local: b is not matching primitive, had: Object, needed: long
Auto-boxing loop arg: b

This is interesting for several reasons. For one, if the arg to recur is a let form, there is no warning:

(fn [] (loop [b 0] (recur (let [a 1] a))))

Also, the compiler appears to understand the return type of loop forms just fine:

(use '[clojure.contrib.repl-utils :only [expression-info]])
(expression-info '(loop [a 1] a))
;=> {:class long, :primitive? true}

The problem can of course be worked around using an explicit cast on the loop form:

(fn [] (loop [b 0] (recur (long (loop [a 1] a)))))

Reported by leafw in IRC: http://clojure-log.n01se.net/date/2011-01-03.html#10:31

[CLJ-1154] Compile.java closes out preventing java from reporting exceptions

Fri, 12 Apr 2013 09:31:03 -0500

I was trying to compile a project that has some native dependencies. I am using clojure-maven-plugin version 1.3.13 with Maven 2.0. I forgot to set java.library.path properly so that the native library could be found, and only got an error of

[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Clojure failed.
[INFO] ------------------------------------------------------------------------

I traced this down to Compile.java, where it is flushing and closing

out

in the finally block. The JVM uses out to write out a stack trace for any uncaught exceptions. When out is closed it is unable to write out the stack trace for the UnsatisfiedLinkError that was being thrown. This made it very difficult to debug what was happening.

[CLJ-823] Piping seque into seque can deadlock

Fri, 12 Apr 2013 09:23:49 -0500

I'm not sure if this is a supported scenario, but the following deadlocks in Clojure 1.3:

(let [xs (seque (range 150000))
ys (seque (filter odd? xs))]
(apply + ys))

As I understand it, the problem is that ys' fill takes place on an agent thread, so when it calls xs' drain, the (send-off agt fill) does not immediately trigger xs' fill, but is instead put on the nested list to be performed when ys' agent returns. Unfortunately, ys' fill will eventually block trying to take from xs, and so it never returns and the pending send-offs are never sent. Wrapping the send-off in drain to:

(future (send-off agt fill))

is a simple (probably not optimal) way to fix the deadlock.

[CLJ-1157] Classes generated by gen-class aren't loadable from remote codebase for mis-implementation of static-initializer

Fri, 12 Apr 2013 09:19:05 -0500

When a client program uses a remote service which uses RMI, and the service returns a object which created with gen-class with clojure as the return value, the return value is not loadable at client side.

At client side, a following exeption will be thrown.

Exception in thread "main" java.lang.ExceptionInInitializerError
        at java.io.ObjectStreamClass.hasStaticInitializer(Native Method)
        at java.io.ObjectStreamClass.computeDefaultSUID(ObjectStreamClass.java:1723)
        at java.io.ObjectStreamClass.access$100(ObjectStreamClass.java:69)
        at java.io.ObjectStreamClass$1.run(ObjectStreamClass.java:247)
        at java.io.ObjectStreamClass$1.run(ObjectStreamClass.java:245)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.io.ObjectStreamClass.getSerialVersionUID(ObjectStreamClass.java:244)
        at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:600)
        at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1601)
        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1514)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1750)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
        at sun.rmi.server.UnicastRef.unmarshalValue(UnicastRef.java:324)
        at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:173)
        at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:194)
        at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:148)
        at $Proxy0.getResult(Unknown Source)
        at client.SampleClient$_main.doInvoke(SampleClient.clj:12)
        at clojure.lang.RestFn.invoke(RestFn.java:397)
        at clojure.lang.AFn.applyToHelper(AFn.java:159)
        at clojure.lang.RestFn.applyTo(RestFn.java:132)
        at client.SampleClient.main(Unknown Source)
 Caused by: java.io.FileNotFoundException: Could not locate remoteserver/SampleInterfaceImpl__init.class or remoteserver/SampleInterfaceImpl.clj on classpath: 
        at clojure.lang.RT.load(RT.java:434)
        at clojure.lang.RT.load(RT.java:402)
        at clojure.core$load$fn__5039.invoke(core.clj:5520)
        at clojure.core$load.doInvoke(core.clj:5519)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at clojure.lang.Var.invoke(Var.java:415)
        at remoteserver.SampleInterfaceImpl.<clinit>(Unknown Source)
        ... 23 more

HOW TO REPRODUCT THIS ISSUE

If you want to see this issue at your computer, clone my example project from my github.

git clone git://github.com/tyano/clojure_genclass_fix.git

and build them (You must have installed Leiningen 2):

cd clojure_genclass_fix
sh build.sh

start rmiregistry:

rmiregistry &

start remoteserver:

cd remoteserver
sh start.sh

You will see a message "Server ready. " or "Server ready. (rebind)".

At last, start client program:

cd ../client
sh start.sh

Without my patch, you will see a same Exception described above. But with clojure with my patch, you will see a right response message: "response = this is sample."

THE REASON

The reason of this problem is in bytecodes generated by gen-class. A gen-classed class (in this case, SampleInterfaceImpl.class) uses a static-initializer for loading SampleInterfaceImpl__init.class (which load other classes which implements functions in the class). The static-initializer is like bellow: (the following code is decompiled with JD - http://java.decompiler.free.fr/?q=jdgui )

static
  {
    RT.var("clojure.core", "load").invoke("/remoteserver/SampleInterfaceImpl");
  }

Very simple code. it seems non-problematic. But RT.load changes the classloader for loading __init.class in the processing! RT.load in default uses a context-classloader for loading classes. But all classes depending on a gen-classed class must be loaded a same classloader with a main gen-classed class. In this case, RT.load must use a remote URLClassLoader which load a main class.

So, gen-class must be create bytecodes that is same with the following java code.

static
  {
    Var.pushThreadBindings(RT.map(new Object[] { Compiler.LOADER, SampleInterfaceImpl.class.getClassLoader() }));
    try {
        RT.var("clojure.core", "load").invoke("/remoteserver/SampleInterfaceImpl");
    }
    finally 
    {
        Var.popThreadBindings();
    }
  }

With this code, RT.load will uses a same classloader which load SampleInterfaceImpl.class.
My patch for gen-class will create bytecodes equal to the above example.

You can use an attached patch '20130204_fix_classloader.diff', or pull 'fix_classloader' branch from my github repositry ( git@github.com:tyano/clojure.git ).

[CLJ-1179] distinct? does not accept zero arguments

Fri, 12 Apr 2013 09:12:55 -0500

distinct? cannot be invoked with zero arguments. When using the pattern (apply distinct? x), this is bothersome as you have to check whether x is empty or not. It is also logical that distinct? should return true if no arguments are given, since there are no duplicates.

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

user=> (apply distinct? [])
ArityException Wrong number of args (0) passed to: core$distinct-QMARK-  clojure.lang.AFn.throwArity (AFn.java:437)

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

I would expect distinct? to return true whenever given zero arguments.

What version are you using?

This was tested under Clojure 1.4 and Clojure 1.5.

[CLJ-1036] Util/hasheq should be hashing a BigInteger to the same values as Long, and BigInt

Fri, 12 Apr 2013 08:48:23 -0500

The doc string for hash states that it defines a hash code function that is consistent with =, but for java.math.BigInteger hash is not consistent with =.

user=> (apply = [(Long. -1) -1N (biginteger -1)])
true
user=> (map hash [(Long. -1) -1N (biginteger -1)])
(0 0 -1)
user=>

It is possible to have a PHM with two key/value pairs where the keys are equal, and the hash codes are different:

user=> (assoc clojure.lang.PersistentHashMap/EMPTY (biginteger -1) :oops! -1N :one)
{-1N :one, -1 :oops!}

The expected behavior is the same as PersistentArrayMap, which does not have this issue, because it does not hash its keys:

user=> (assoc clojure.lang.PersistentArrayMap/EMPTY (biginteger -1) :oops! -1N :one)
{-1 :one}

This same misbehavior also occurs for Doubles and Floats:

thalia.core=> (apply = [(Float. 1e9) (Double. 1e9)])
true
thalia.core=> (map hash [(Float. 1e9) (Double. 1e9)])
(1315859240 1104006501)

That leads to the same difference in array-map and hash-map behavior as above for BigInteger and BigInt.

[CLJ-1005] Use transient map in zipmap

Thu, 11 Apr 2013 18:19:28 -0500

The attached patch changes zipmap to use a transient map internally. The definition is also moved so that it resides below that of #'transient. The original definition is commented out (like that of #'into).

[CLJ-935] clojure.string/trim uses different defn of whitespace as triml, trimr

Thu, 11 Apr 2013 17:36:32 -0500

clojure.string/triml and trimr use Character/isWhitespace to determine whether a character is whitespace, but trim uses some other definition of white space character. For example:

user=> (use 'clojure.string)
nil
user=> (def s " \u2002 foo")
#'user/s
user=> (trim s)
"? foo"
user=> (triml s)
"foo"

The attached patch changes trim to use Character/isWhitespace. I suppose other possibilities are to change triml and trimr to use trim's notion of whitespace, whatever that is, or to just leave these functions inconsistent with each other. It does seem that it would be a nice property that (trim s) is equal to (triml (trimr s)) for all strings.

The patch also changes triml to only call .length on s once.

[CLJ-1185] `reductions should respect `reduced

Wed, 10 Apr 2013 17:08:45 -0500

This returns 16:

(reduce (fn [acc x]
          (let [x' (* x x)]
            (if (> x' 10)
              (reduced x')
              x')))
        (range))

But replacing `reduce with `reductions will never terminate:

(reductions (fn [acc x]
              (let [x' (* x x)]
                (if (> x' 10)
                  (reduced x')
                  x')))
            (range))

This is because `reductions ignores 'clojure.lang.Reduced, it never tests for `reduced?

I know that I only just discovered the `reduced, function, but `reductions is a big part of my debugging process, so it's unfortunate that they don't work together.

[CLJ-1196] eval of defrecord instance with no fields produces {}, not itself

Wed, 10 Apr 2013 11:42:33 -0500

user> (defrecord Foo [])
user.Foo
user> (Foo.)
#user.Foo{}
user> (eval (Foo.))
{}

user> (defrecord Foo [a b])
user.Foo
user> (eval (Foo. 1 2))
#user.Foo{:a 1, :b 2}

As you can see, evaluating the record with no fields loses the type information. This came up in code that uses records to describe argument schema information for functions in a macro, with no direct use of 'eval'. It is unexpected because of the inconsistency between empty and non-empty defrecords, and because the Clojure docs say 'Any object other than those discussed above will evaluate to itself.'

http://clojure.org/evaluation

I'm happy to elaborate on the use case if there are questions.

[CLJ-1197] Allow fold to parallelize over lazy sequences

Wed, 10 Apr 2013 10:34:09 -0500

This patch implements foldable-seq, which allows fold to parallelize over a lazy sequence. See this conversation on the Clojure mailing list:

https://groups.google.com/forum/#!msg/clojure/8RKCjF00ukQ/b5mmmOB5Uh4J

The patch is code only, sadly. No tests because I've not been able to find any existing tests for fold:

https://groups.google.com/d/msg/clojure-dev/plQ16L1_FC0/CIyMVIgSZkkJ

However, I have tested it in a separate project successfully.

[CLJ-1195] emit-hinted-impl expands to non-ns-qualified invocation of 'fn'

Tue, 9 Apr 2013 22:23:47 -0500

(ns plumbing.tmp
(:refer-clojure :exclude [fn]))

(defprotocol Foo
(foo [this]))

(extend-protocol Foo
Object
(foo [this]))

yields

CompilerException java.lang.RuntimeException: Unable to resolve symbol: fn in this context, compiling/Users/w01fe/prismatic/prismatic/plumbing/src/plumbing/tmp.clj:7:1)

This makes it difficult to construct a namespace that provides a replacement def for fn.

[CLJ-1053] Locals still cleared too aggressively on delay in specific cases

Tue, 9 Apr 2013 11:55:52 -0500

This seems to be an extension of #CLJ-232. Locals are still cleared too aggressively in some specific instances: If the delay throws an exception when realized, and you dereference a local within the delay, the local may or may not be cleared depending on its need in the tail positions (without any obvious pattern). Examples of functions which works as intended and doesn't work as intended follows.

(def d (let [y (delay 0)]
         (delay (if (zero? @y) (/ 0 0) (/ @y 1))))) ; works properly

(def d (let [y (delay 0)]
         (delay (if (zero? @y) (/ 0 0) (/ 1 1))))) ; does not work properly

(def d (let [y (delay 0)]
         (delay (if (zero? @y) (/ @y 0) (/ 1 1))))) ; does not work properly

(def d (let [y (delay 0)]
         (delay (if (zero? @y) (/ @y 0) (/ @y 1))))) ; does not work properly

(def d (let [y (delay 0)]
         (delay @y (/ 0 0)))) ; does not work properly

(def d (let [y (delay 0)]
         (delay @y (/ 0 0) @y))) ; works properly

By "works", d will throw "ArithmeticException Divide by zero" every single time it is dereferenced. By "does not work", d will throw "ArithmeticException Divide by zero" on first dereferencing, but from second and onwards it will throw "NullPointerException [trace missing]".

[CLJ-1194] Typo in core.reducers

Tue, 9 Apr 2013 04:49:58 -0500

As far as I can say, there is a typo in core.reducers (and therefore core.reducers/monoid is unusable in 1.5.1):

https://github.com/clojure/clojure/blob/master/src/clj/clojure/core/reducers.clj#L321

(fn m <-- this
    ([] (ctor))
    ([a b] (op a b))))

Should I submit a patch to fix this?

[CLJ-937] cl-format prints ratio arguments with bad format for E, F, G directives

Mon, 8 Apr 2013 12:02:21 -0500

user=> (use 'clojure.pprint)
nil
user=> (cl-format false "~e" 4/5)
"4./5E+2"
user=> (cl-format false "~f" 4/5)
"4/5.0"
user=> (cl-format false "~g" 4/5)
"4/5. "

Patch changes cl-format so that when E, F, or G directive is used, the corresponding arg is coerced from a clojure.lang.Ratio to a double before formatting.

[CLJ-1192] vec function is substantially slower than into function

Sun, 7 Apr 2013 17:50:41 -0500

(vec coll) and (into [] coll) do exactly the same thing. However, due to into using transients, it is substantially faster. On my machine:

(time (dotimes [_ 100] (vec (range 100000))))
"Elapsed time: 732.56 msecs"

(time (dotimes [_ 100] (into [] (range 100000))))
"Elapsed time: 491.411 msecs"

This is consistently repeatable.

Since vec's sole purpose is to transform collections into vectors, it should do so at the maximum speed available.

[CLJ-976] Implement reader literal and print support for PersistentQueue data structure

Sat, 6 Apr 2013 08:07:20 -0500

Clojure's PersistentQueue structure has been in the language for quite some time now and has found its way into a fair share of codebases. However, the creation of queues is a two step operation often of the form:

(conj clojure.lang.PersistentQueue/EMPTY :a :b :c)

;=> #<PersistentQueue clojure.lang.PersistentQueue@78d5f6bc>

A better experience might be the following:

#queue [:a :b :c]

;=> #queue [:a :b :c]

(pop #queue [:a :b :c])

;=> #queue [:b :c]

This syntax is proposed and discussed in the Clojure-dev group at https://groups.google.com/forum/?fromgroups#!topic/clojure-dev/GQqus5Wycno

Open question: Should the queue literal's arguments eval? The implications of this are illustrated below:

;; non-eval case
#queue [1 2 (+ 1 2)]

;=> #queue [1 2 (+ 1 2)]


;; eval case
#queue [1 2 (+ 1 2)]

;=> #queue [1 2 3]

The answer to this open question will determine the implementation.

[CLJ-1191] Improve apropos to show some indication of namespace of symbols found

Fri, 5 Apr 2013 13:34:10 -0500

apropos does find all symbols in all namespaces that match the argument, but the return value gives no clue as to which namespace the found symbols are in. It can even return multiple occurrences of the same symbol, which only gives a clue that the symbol exists in more than one namespace, but not which ones. For example:

user=> (apropos "replace")
(postwalk-replace prewalk-replace replace re-quote-replacement replace replace-first)

It would be nice if the returned symbols could indicate the namespace, either always, or if the found symbol is not in the current namespace.

[CLJ-1165] Forbid varargs defprotocol/definterface method declarations because those cannot be defined anyway

Thu, 4 Apr 2013 19:24:27 -0500

Protocol, interface method declarations don't allow for varags. Currently, for example

  (defprotocol FooBar
    (foo [this & more]))

compiles just fine, and & is interpreted as a usual argument that happens to be
named & without special meaning. But clearly, the user wanted to specify a
varags parameter here. The same applies to definterface.

Similarly, providing method implementations via defrecord, deftype, and reify
don't allow for varags (but dynamic extensions via extend do).

So this patch makes defprotocol and definterface throw an
IllegalArgumentException if a user tries to use varargs in method signatures.

Similarly, defrecord, deftype, and reify throw an IllegalArgumentException if
any method implementation arglist contains a varargs argument.

This patch is a cut-down variant of my patch to http://dev.clojure.org/jira/browse/CLJ-1024
which has been reverted shortly before Clojure 1.5 was released. The ~~CLJ-1024~~ patch
was the same as this one, but it has also forbidden destructuring in defprotocol and
definterface. This was a bit too much, because although destructuring has no
semantic meaning with method declarations, it still can serve a documentation purpose.

This has been discussed on the list: https://groups.google.com/d/topic/clojure-dev/qjkW-cv8nog/discussion

[CLJ-1190] Javadoc for public Java API

Wed, 3 Apr 2013 06:51:13 -0500

We should publish javadoc for http://dev.clojure.org/jira/browse/CLJ-1188.

make sure to publish on the the public API classes and interfaces
if IFn remains part of public interface, find javadoc control knob to disable including the nested interfaces dealing with primitives
automate publishing the docs somewhere (javadoc.clojure.org?)

This ticket should wait until ~~CLJ-1188~~ is ok'ed.

[CLJ-1189] Map-destructuring :or fumble needs compiler warning

Sun, 31 Mar 2013 08:02:44 -0500

Here is a map-destructuring blunder that I wish the compiler warned about:

(defn server
[{servlet ::servlet
type ::type
:or {::type :jetty}
:as service-map}]

It would be splendid to get a warning that :or keys that are not symbols being bound have no effect.

The incomplete code snippet above comes from Pedestal.service 0.1.0.

Here is a complete one-line example with the coding error:

user> (defn picnic [{botulism :botulism :or {:botulism 6}}] botulism)
#'user/picnic
user> (picnic {})
nil
user> ;; I intended 6.

[CLJ-1026] Mixed end-of-line endings in the source code

Sat, 30 Mar 2013 08:44:15 -0500

While examining some of the Clojure source code, I discovered that some files had mixed line endings, or CRLF line endings on a non-Windows box. Using .gitattributes, we can correct that so that files have the right endings for the platform that it's on.

Recent Activity (Clojure JIRA)

[CLJ-827] unsigned-bit-shift-right

[CLJ-322] Enhance AOT compilation process to emit classfiles only for explicitly-specified namespaces

[CLJ-1016] Global scope overrides lexical scope for classes (Clojure assumes no classes in default package / Clojure cannot handle yFiles JARs in classpath)

[CLJ-1074] Read/print round-trip for +/-Infinity and NaN

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

[CLJ-1107] 'get' should throw exception on non-Associative argument

[CLJ-850] Hinting the arg vector of a primitive-taking fn with a non-primitive type results in AbstractMethodError when invoked

[CLJ-1193] bigint, biginteger throw on double values outside of long range

[CLJ-1125] Clojure can leak memory when used in a servlet container

[CLJ-1083] Incorrect ArityException message for function names containing ->

[CLJ-1171] Compiler macro for clojure.core/instance? disregards lexical shadows on class names

Summary

Patches

Data

Test case

Culprit method

List Discussion

Tangent

[CLJ-1161] sources jar has bad versions.properties resource

[CLJ-1175] NPE in clojure.lang.Delay/deref

[CLJ-1176] clojure.repl/source fails when *read-eval* bound to :unknown

[CLJ-1187] Clojure loses quoted metadata on empty literals

[CLJ-944] compiler makes different concrete maps then the reader

[CLJ-1121] -> and ->> have unexpected behavior when combined with unusual macros

[CLJ-873] Allow the function / to be referred to in namespaces other than clojure.core

[CLJ-1122] Add contributing.md file to github repository (shows clear message on issues/pull request create form)

[CLJ-1072] Replace old metadata reader macro syntax

[CLJ-896] Make browse-url aware of xdg-open

[CLJ-863] interleave should accept 1 or 0 arguments

[CLJ-783] clojure.inspector/inspect-tree doesn't work on sets --patch in the description by Jason Wolfe

[CLJ-1164] typos in instant.clj

[CLJ-1143] Minor correction to doc string of ns macro

[CLJ-1101] *default-data-reader-fn* should be set!-able in REPL

[CLJ-1099] better error message when passing non-seq to seq

[CLJ-908] Functions with metadata print poorly

[CLJ-1018] range's behavior is inconsistent

[CLJ-1078] Added queue, queue* and queue? to clojure.core

[CLJ-1210] error message for (clojure.java.io/reader nil) — consistency for use with io/resource

[CLJ-1201] There should also be writing in clojure.edn

[CLJ-999] Wrong link in gh-pages index (api-index.html)

[CLJ-1147] Threading macro (->) does not permit inline function declarations

[CLJ-1183] java interop - cannot call a final method on non-public superclass

[CLJ-1131] Importing a non-existent class causes an exception that does not fully identify the source file

[CLJ-1173] One-arg protocol functions whose name begins in a dash generates a call to a wrong field in the emitted code

[CLJ-1117] Partition does not follow docs

[CLJ-1209] Teach clojure.test reporting about ex-info/ex-data

[CLJ-1207] Importing a class that does not exist fails to report the name of the class that did not exist

[CLJ-1202] protocol fns with dashes may get compiled into property access when used higher order

[CLJ-866] Provide a clojure.test function to run a single test case with fixtures

[CLJ-766] Implicit casting behaviour of into-array differs from -array

[CLJ-1208] Namespace is not loaded on defrecord class init

[CLJ-428] subseq, rsubseq enhancements to support priority maps?

[CLJ-1203] Fallback to hash-based comparison for non-Comparables in Util.compare()

[CLJ-1206] 'eval' of closures or fns with runtime metadata within a call expr yields "No matching ctor found" exceptions

[CLJ-1118] inconsistent numeric comparison semantics between BigDecimal and other Numerics

[CLJ-1204] hash is inconsistent with = for many BigInteger values

[CLJ-1205] Update Maven build for Nexus 2.4

[CLJ-1200] RestFn & ArraySeq performance

[CLJ-889] Specifically allow '.' inside keywords

[CLJ-1182] Regexp are never equal

[CLJ-1199] Record values are not 'eval'uated, unlike values of PersistentMap:

[CLJ-1198] Apply metadata to primitive fns causes them to lose their primitive-ness

[CLJ-1188] Public Java API

[CLJ-196] *file* returns "NO_SOURCE_PATH", but the doc says it should be nil

[CLJ-124] GC Issue 120: Determine mechanism for controlling automatic shutdown of Agents, with a default policy and mechanism for changing that policy as needed

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

[CLJ-1058] StackOverflowError on exception in reducef for PersistentHashMap fold

[CLJ-420] Some compiler exceptions erroneously using REPL line numbers.

[CLJ-1105] defrecord classes implement IPersistentCollection but not .empty, clojure.walk assumes collections support empty

[CLJ-787] transient blows up when passed a vector created by subvec

[CLJ-701] Compiler loses 'loop's return type in some cases

[CLJ-1154] Compile.java closes out preventing java from reporting exceptions

[CLJ-823] Piping seque into seque can deadlock

[CLJ-1157] Classes generated by gen-class aren't loadable from remote codebase for mis-implementation of static-initializer

HOW TO REPRODUCT THIS ISSUE

THE REASON

[CLJ-1179] distinct? does not accept zero arguments

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

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

[CLJ-1176] clojure.repl/source fails when read-eval bound to :unknown

[CLJ-1101] default-data-reader-fn should be set!-able in REPL

[CLJ-196] file returns "NO_SOURCE_PATH", but the doc says it should be nil