Clojure JIRA

[CLJ-47] GC Issue 43: Dead code in generated bytecode

Fri, 8 Oct 2010 10:21:00 -0500

Reported by Levente.Santha, Jan 11, 2009
The bug was described in detail in this thread: http://groups.google.com/
group/clojure/browse_thread/thread/81ba15d7e9130441

For clojure.core$last__2954.invoke the correct bytecode would be (notice 
the removed "goto    65" after "41:  goto    0"):

public java.lang.Object invoke(java.lang.Object)   throws 
java.lang.Exception;
  Code:
   0:   getstatic       #22; //Field const__0:Lclojure/lang/Var;
   3:   invokevirtual   #37; //Method clojure/lang/Var.get:()Ljava/lang/
Object;
   6:   checkcast       #39; //class clojure/lang/IFn
   9:   aload_1
   10:  invokeinterface #41,  2; //InterfaceMethod clojure/lang/IFn.invoke:
(Ljava/lang/Object;)Ljava/lang/Object;
   15:  dup
   16:  ifnull  44
   19:  getstatic       #47; //Field java/lang/Boolean.FALSE:Ljava/lang/
Boolean;
   22:  if_acmpeq       45
   25:  getstatic       #22; //Field const__0:Lclojure/lang/Var;
   28:  invokevirtual   #37; //Method clojure/lang/Var.get:()Ljava/lang/
Object;
   31:  checkcast       #39; //class clojure/lang/IFn
   34:  aload_1
   35:  invokeinterface #41,  2; //InterfaceMethod clojure/lang/IFn.invoke:
(Ljava/lang/Object;)Ljava/lang/Object;
   40:  astore_1
   41:  goto    0
   44:  pop
   45:  getstatic       #26; //Field const__1:Lclojure/lang/Var;
   48:  invokevirtual   #37; //Method clojure/lang/Var.get:()Ljava/lang/
Object;
   51:  checkcast       #39; //class clojure/lang/IFn
   54:  aload_1
   55:  aconst_null
   56:  astore_1
   57:  invokeinterface #41,  2; //InterfaceMethod clojure/lang/IFn.invoke:
(Ljava/lang/Object;)Ljava/lang/Object;
   62:  areturn

Our JIT reported incorrect stack size along the basic block introduced by 
the unneeded goto.
The bug was present in SVN rev 1205.

[CLJ-113] GC Issue 109: RT.load's "don't load if already loaded" mechanism breaks ":reload-all"

Tue, 9 Aug 2011 20:31:28 -0500

Reported by scgilardi, Apr 24, 2009

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

"require" and "use" support a ":reload-all" flag that is intended to  
cause the specified libs to be reloaded along with all libs on which  
they directly or indirectly depend. This is implemented by temporarily  
binding a "loaded-libs" var to the empty set and then loading the  
specified libs.

AOT compilation added another "already loaded" mechanism to  
clojure.lang.RT.load() which is currently not sensitive to a "reload-
all" being in progress and breaks its operation in the following case:

        A, B, and C are libs
        A depends on B. (via :require in its ns form)
        B depends on C. (via :require in its ns form)
        B has been compiled (B.class is on classpath)

        At the repl I "require" A which loads A, B, and C (either from
class files or clj files)
        I modify C.clj
        At the repl I "require" A with the :reload-all flag, intending to  
pick up the changes to C
        C is not reloaded because RT.load() skips loading B: B.class
exists, is already loaded, and B.clj hasn't changed since it was compiled.


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

I expect :reload-all to be effective. It isn't.

What version are you using?

svn 1354, 1.0.0RC1

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

http://groups.google.com/group/clojure/browse_frm/thread/9bbc290321fd895f/e6a967250021462a#e6a967250021462a

Please provide any additional information below.

I'll upload a patch soon that creates a "*reload-all*" var with a  
root binding of nil and code to bind it to true when the current  
thread has a :reload-all call pending. When *reload-all* is true,  
RT.load() will (re)load all libs from their ".clj" files even if  
they're already loaded.

The fix for this may need to be coordinated with a fix for issue #3.

[CLJ-127] DynamicClassLoader's call to ClassLoader.getSystemClassLoader is prohibited in some environments

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

Currently, clojure.lang.DynamicClassLoader's constructor has the
following call to super():

super(EMPTY_URLS,
      (Thread.currentThread().getContextClassLoader() == null ||
        Thread.currentThread().getContextClassLoader() == ClassLoader.getSystemClassLoader()) ?
          Compiler.class.getClassLoader() : Thread.currentThread().getContextClassLoader());

That call to ClassLoader.getSystemClassLoader() is forbidden by Google
AppEngine's security policies. That restricts you from being able to
load any resources from the classpath that haven't been AOT-compiled.
I've verified that just removing that removing the " ||
Thread.currentThread().getContextClassLoader() ==
ClassLoader.getSystemClassLoader()" does in fact result in something
that works in GAE (as far as my needs go). Unfortunately, I'm not sure
whether that breaks anything, which, presumably, it does.

[CLJ-270] defn-created fns inherit old metadata from the Var they are assigned to

Tue, 24 Aug 2010 06:23:00 -0500

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

user> (def #^{:foo "bar"} x 5)
#'user/x
user> (meta #'x)
{:ns #<Namespace user>, :name x, :file "NO_SOURCE_FILE", :line 1, :foo "bar"}
user> (defn x [] 5)
#'user/x
user> (meta #'x)
{:ns #<Namespace user>, :name x, :file "NO_SOURCE_FILE", :line 1, :arglists ([])}
user> (meta x)
{:ns #<Namespace user>, :name x, :file "NO_SOURCE_FILE", :line 1, :foo "bar"}

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

I expect (meta #'x) to evaluate to the value of the final (meta x) in the above.

What version are you using?

Current master (commit 61202d2ff6925002400a9843e8fbd080f3bef3a5).

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

http://groups.google.com/group/clojure/browse_thread/thread/4c7151aa9c4d919c/d1b033ef5a13dd89?lnk=gst&q=off-by-one#d1b033ef5a13dd89

Prompted by discussion at

http://groups.google.com/group/clojure/browse_thread/thread/6553d48c981019eb/3c55b0bd43a5d8e9?lnk=gst&q=off-by-one#3c55b0bd43a5d8e9

Initial attempt at a diagnosis:

I think this is due to DefExpr's eval method binding the Var to init.eval() first and attaching the supplied metadata to the Var later – see Compiler.java lines 341-352. (Note the Var is always already in place when init.eval() is called, regardless of whether it existed prior to the evaluation of the def / defn.) Thus the init expression supplied by defn sees the old (and wrong) metadata on the Var.

[CLJ-252] Support typed non-primitive fields in deftype

Tue, 24 Aug 2010 06:07:00 -0500

Right now hints are accepted but not used as field type.

[CLJ-326] add :as-of option to refer

Tue, 24 Aug 2010 10:19:00 -0500

Discussed here: http://groups.google.com/group/clojure-dev/msg/74af612909dcbe56

:as-of allows library authors to specify a known subset of vars to refer from clojure (or any other library which would use :added metadata).

(ns foo (:refer-clojure :as-of "1.1")) is equivalent to (ns foo (:refer-clojure :only [public-documented-vars-which-already-existed-in-1.1]))

[CLJ-163] Enhance = and == docs

Tue, 24 Aug 2010 13:04:00 -0500

Enhance = and == docs as far as numbers handling is concerned (make them self referenced, make clear what == offers beyond = -except that it will only work for numbers)

[CLJ-42] GC Issue 38: When using AOT compilation, "load"ed files are not reloaded on (require :reload 'name.space)

Tue, 24 Aug 2010 06:44:00 -0500

Reported by m...@kotka.de, Jan 07, 2009
What (small set of) steps will reproduce the problem?

1. Create a file src/foo.clj

cat >src/foo.clj <<EOF
(ns foo (:load "bar"))
EOF

2. Create a file src/bar.clj

cat >src/bar.clj <<EOF
(clojure.core/in-ns 'foo)
(def x 8)
EOF

3. Start Clojure Repl: java -cp src:classes clojure.main -r

4. Compile the namespace.

user=> (compile 'foo)
foo

5. Require the namespace
user=> (require :reload-all :verbose 'foo)
(clojure.core/load "/foo")
(clojure.core/load "/bar")

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

6. Re-Require the namespace

user=> (require :reload-all :verbose 'foo)
(clojure.core/load "/foo")

Only the "master" file is loaded, but not the bar file.
Expected would have been to also load the bar file.
Changes to bar.clj are not reflected, and depending
on the setting (eg. using multimethods in foo from
a different namespace) code may be corrupted.

What version are you using?

SVN rev. 1195

[CLJ-259] clojure.lang.Reflector.invokeMatchingMethod is not complete (rejects pontentially valid method invocations)

Tue, 24 Aug 2010 15:12:00 -0500

There exists invoke expressions on instances, where Java is able to perform the call, yet clojure is not reflectively.
The problem is when the declaringClass of the found method is not public then the call to getAsMethodOfPublicBase uses the found method or searching for classes/interfaces that contain/define this method yet are declared publicly.

This restricts the possible search space. I suggest that if target is not null (e.g. is not a static method), the target.getClass() should be used instead as a root for getAsMethodOfPublicBase.
This fixes my issue.

[CLJ-666] Add support for Big* numeric types to Reflector

Thu, 15 Nov 2012 20:07:39 -0600

This should work as expected, for example:

(Integer. 1N)

Probably for BigInt, BigInteger, and BigDecimal.

Method to look at is c.l.Reflector.paramArgTypeMatch, per Rich in irc.

[CLJ-415] smarter assert (prints locals)

Sun, 18 Nov 2012 01:06:07 -0600

Here is an implementation you can paste into a repl. Feedback wanted:

(defn ^{:private true} local-bindings
  "Produces a map of the names of local bindings to their values."
  [env]
  (let [symbols (map key env)]
    (zipmap (map (fn [sym] `(quote ~sym)) symbols) symbols)))

(defmacro assert
  "Evaluates expr and throws an exception if it does not evaluate to
 logical true."
  {:added "1.0"}
  [x]
  (when *assert*
    (let [bindings (local-bindings &env)]
      `(when-not ~x
         (let [sep# (System/getProperty "line.separator")]
           (throw (AssertionError. (apply str "Assert failed: " (pr-str '~x) sep#
                                          (map (fn [[k# v#]] (str "\t" k# " : " v# sep#)) ~bindings)))))))))

[CLJ-457] lazy recursive definition giving incorrect results

Mon, 3 Dec 2012 11:21:29 -0600

If you define a global data var in terms of a lazy sequence referring to that same var, you can get different results depending on the chunkiness of laziness of the functions being used to build the collection.

Clojure's lazy sequences don't promise to support this, but they shouldn't return wrong answers. In the example given in http://groups.google.com/group/clojure/browse_thread/thread/1c342fad8461602d (and repeated below), Clojure should not return bad data. An error message would be good, and even an infinite loop would be more reasonable than the current behavior.

(Similar issue reported here: https://groups.google.com/d/topic/clojure/yD941fIxhyE/discussion)

(def nums (drop 2 (range)))
(def primes (cons (first nums)
             (lazy-seq (->>
               (rest nums)
               (remove
                 (fn [x]
                   (let [dividors (take-while #(<= (* % %) x)
primes)]
                     (println (str "primes = " primes))
                     (some #(= 0 (rem x %)) dividors))))))))
(take 5 primes)

It prints out:
(primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
primes = (2)
2 3 5 7 9)

[CLJ-2] Scopes

Thu, 8 Mar 2012 04:01:38 -0600

Add the scope system for dealing with resource lifetime management

[CLJ-366] Multiplatform command-line clojure launcher

Fri, 10 Dec 2010 10:13:46 -0600

Clojure needs a lower barrier of entry, long java commands scare people away! We need a script that conveniently launches a clojure repl or executes clojure files, much like the ruby/python/perl/other-favorite-interpreted-language behavior.

NOTES:

From Russ Olson (regarding Dejure/Dejour):

I just fixed a bunch of bugs in the script, so make sure you get the latest from download from: http://github.com/russolsen/dejour
After looking at jruby, scala, and groovy, it seems that the only way to do this right on windows is to write a C or C++ program and have a .exe.

[CLJ-700] contains? broken for TransientMaps

Tue, 28 Aug 2012 17:48:49 -0500

(contains? (transient {:x "fine"}) :x)

false

also

(contains? (transient (hash-map :x "fine")) :x)

false

[CLJ-84] GC Issue 81: compile gen-class fail when class returns self

Fri, 10 Dec 2010 09:30:52 -0600

Reported by davidhaub, Feb 14, 2009

When attempting to compile the following program, clojure fails with a
ClassNotFoundException.  It occurs because one of the methods returns the
same class that is being generated.  If the returnMe method below is
changed to return an Object, the compile succeeds.

Beware when testing! If the classpath contains a class file (say from a
prior successful build when the returnMe method was changed to return an
object), the compile will succeed.  Always clear out the
clojure.compile.path prior to compiling.

;badgenclass.clj
(ns badgenclass
  (:gen-class
     :state state
     :methods
     [[returnMe [] badgenclass]]
     :init init))
(defn -init []
  [[] nil])

(defn -returnMe [this]
  this)

#!/bin/sh
rm -rf classes
mkdir classes
java -cp lib/clojure.jar:classes:. -Dclojure.compile.path=classes \
clojure.lang.Compile badgenclass


Comment 1 by chouser, Mar 07, 2009

Attached is a patch that accepts strings or symbols for parameter and return class
names, and generates the appropriate bytecode without calling Class/forName.  It
fixes this issue, but because 'ns' doesn't resolve :gen-class's arguments, class
names aren't checked as early anymore.  :gen-class-created classes with invalid
parameter or return types can even be instantiated, and no error will be reported
until the broken method is called.

One possible alternative would be to call Class/forName on any symbols given, but
allow strings to use the method given by this patch.  To return your own type, you'd
need a method defined like:

  [returnMe [] "badgenclass"]

Any thoughts?

[CLJ-69] GC Issue 66: Add "keyset" to Clojure; make .keySet for APersistentMap return IPersistentSet

Fri, 10 Dec 2010 08:48:40 -0600

Reported by wolfe.a.jason, Feb 04, 2009

Describe the feature/change.

Add "keyset" to Clojure; make .keySet for APersistentMap return an
IPersistentSet

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

http://groups.google.com/group/clojure/browse_thread/thread/66e708e477ae992f/ff3d8d588068b60e?hl=en#ff3d8d588068b60e

-----------------------------------------------------

A patch is attached.  Some notes:

I chose to add a "keyset" function, rather than change the existing "keys",
so as to avoid breaking anything.

The corresponding RT.keyset function just calls .keySet on the argument.
I would have liked to have "keyset" return an IPersistentSet even when
passed a (non-Clojure) java.util.Map, but this seems impossible to do in
sublinear time because of essentially the same limitation mentioned in the
above thread (the Map interface does not support getKey() or entryAt()) --
assuming, again, that "get" is supposed to return the actual (identical?)
key in a set, and not just an .equal key.

I then changed the implementation of .keySet for APersistentMap to
essentially copy APersistentSet.  A more concise alternative would have
been to extend APersistentSet and override the .get method, but that made
me a bit nervous (since if APeristentSet changed this could break). 

Anyway, this is my first patch for the Java side of Clojure, and I'm not
yet solid on the conventions and aesthetics, so
comments/questions/criticisms/requests for revisions are very welcome.

[CLJ-211] Support arbitrary functional destructuring via -> and ->>

Fri, 10 Dec 2010 08:49:03 -0600

Support arbitrary functional destructuring, that is the use of
any function in any destructuring form to help unpack data in
arbitrary ways.

The discussion began here:
http://clojure-log.n01se.net/date/2009-11-17.html#09:31c

The attached patch implements the spec described here:
http://clojure-log.n01se.net/date/2009-11-17.html#10:50a

That is, the following examples would now work:

user=> (let [(-> str a) 1] a)
"1"

user=> (let [[a (-> str b) c] [1 2]] (list a b c))
(1 "2" nil)

user=> (let [(->> (map int) [a b]) "ab"] (list a b))
(97 98)

[CLJ-291] (take-nth 0 coll) redux...

Fri, 10 Dec 2010 08:50:19 -0600

I dont seem to be able make the old ticket uninvalid so here goes
(take-nth 0 coll) causes (at least on Solaris) infinite space and time consumption
It's not a printout error as the following code causes the problem too

(let [j 0
firstprod (apply * (doall (map #(- 1 %) (take-nth j (:props mix)))))]) ; from my parameter update function

I used jvisualvm and the jvm is doing some RNI call - no clojure code is running at all
If left alone it will crash the jvm with all heap space consumed
0 is an InvalidArgument for take-nth
I wouldnt mind if it produced an infinite lazy sequence of nils even though thats wrong
It doesnt do this though it actively destroys the JVM
Its a bug nasty destructive and it took me half a day to figure out what was going on
please let someone fix it!

[CLJ-699] make sure compile paths shares as much code as possible

Fri, 31 Dec 2010 16:01:39 -0600

Issue http://dev.clojure.org/jira/browse/CLJ-697 highlighted the fact that compilation has more than one entry point. Review these entry points and make them share code.

[CLJ-807] hash-maps print-dup as literal, thus can be read as array-maps

Fri, 29 Jul 2011 07:42:26 -0500

Per Rich in ~~CLJ-799~~: "The point of print-dup is type preservation"

user=> (hash-map :k :v)
{:k :v}
user=> (type *1)
clojure.lang.PersistentHashMap
user=> (binding [*print-dup* true] (print-str *2))
"{:k :v}"
user=> (read-string *1)
{:k :v}
user=> (type *1)
clojure.lang.PersistentArrayMap

The cause is due to RT.map conditionally creating an array-map if the size is within the PersistentArrayMap.HASHTABLE_THRESHOLD.

[CLJ-248] Add support for subsets and submaps to sorted Sets/Maps

Sat, 2 Jun 2012 19:08:44 -0500

Currently we can have a subseq of a sorted-set|map-by, but this returns a seq and
not a Set or Map.
Implementing the interfaces java.util.SortedSet and java.util.SortedMap would give
us support for calling .subSet and .subMap.

[CLJ-803] IAtom interface

Mon, 4 Jul 2011 21:18:48 -0500

Atom and the other reference types do not have interfaces and are marked final.

Use cases for interfaces for the reference types include database wrappers. CouchDB behaves exactly like compare-and-set! and is shared, synchronous, independent state, so it makes sense to use the Atom interface to update a CouchDB document.

I talked to Rich about this, and he said "patch welcome for IAtom", complete conversation: http://clojure-log.n01se.net/date/2010-12-29.html#10:04c

[CLJ-735] Improve error message when a protocol method is not found

Fri, 9 Dec 2011 10:05:55 -0600

If you call a protocol function but pass the wrong arity (forget an argument for example), you currently a message that says "No single method ... of interface ... found for function ... of protocol ...". The code in question is getting matching methods from the Reflector and creates this message if the number of matches != 1.

There are really two cases there:

matches == 0 - this happens frequently due to typos
matches > 1 - this presumably happens infrequently

I propose that the == 0 case instead should have slightly different text at the beginning and a hint as to the intended arity within it:

"No method: ... of interface ... with arity ... found for function ... of protocol ...".

The >1 case should have similar changes: "Multiple methods: ... of interface ... with arity ... found for function ... of protocol ...".

Patch is attached. I used case which presumably should have better performance than a nested if/else. I was not sure whether the reported arity should match the actual Java method arity or Clojure protocol function arity (including the target). I did the former.

I did not add a test as I wasn't sure whether checking error messages in tests was appropriate or not. Happy to add that if requested.

[CLJ-731] Create macro to variadically unroll a combinator function definition

Fri, 28 Jan 2011 09:40:05 -0600

Clojure contains a set of combinators that are implemented in a similar, but slightly different way. That is, they are implemented as a complete set of variadic overloads on both the call-side and also on the functions that they return. Visually, they all tend to look something like:

(defn foo
  ([f]
     (fn
       ([] do stuff...)
       ([x] do stuff...)
       ([x y] do stuff...)
       ([x y z] do stuff...)
       ([x y z & args] do variadic stuff...)))
  ([f1 f2]
     (fn
       ([] do stuff...)
       ([x] do stuff...)
       ([x y] do stuff...)
       ([x y z] do stuff...)
       ([x y z & args] do variadic stuff...)))
  ([f1 f2 f3]
     (fn
       ([] do stuff...)
       ([x] do stuff...)
       ([x y] do stuff...)
       ([x y z] do stuff...)
       ([x y z & args] do variadic stuff...)))
  ([f1 f2 f3 & fs]
     (fn
       ([] do stuff...)
       ([x] do stuff...)
       ([x y] do stuff...)
       ([x y z] do stuff...)
       ([x y z & args] do variadic stuff...))))

To build this type of function for each combinator is tedious and error-prone.

There must be a way to implement a macro that takes a "specification" of a combinator including:

1. name
2. docstring
3. do stuff template
4. do variadic stuff template

And builds something like the function foo above. This macro should be able to implement the current batch of combinators (assuming that http://dev.clojure.org/jira/browse/CLJ-730 is completed first for the sake of verification).

[CLJ-1104] Concurrent with-redefs do not unwind properly, leaving a var permanently changed

Fri, 21 Dec 2012 23:05:10 -0600

On 1.4 and latest master:

user> (defn ten [] 10)
#'user/ten
user> (doall (pmap #(with-redefs [ten (fn [] %)] (ten)) (range 20 100)))
(20 21 22 23 24 25 34 27 28 29 30 31 32 33 34 35 36 37 38 39 39 35 42 43 44 45 48 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 79 87 88 89 90 91 92 93 94 95 97 92 98 99)
user> (ten)
79

Not sure if this is a bug per se, but the doc doesn't mention lack of concurrency safety and my expectation was that the original value would always be restored after any (arbitrarily interleaved) sequence of with-redefs calls.

[CLJ-348] reify allows use of qualified name as method parameter

Fri, 1 Mar 2013 12:33:02 -0600

This should complain about using a fully-qualified name as a parameter:

(defmacro lookup []
`(reify clojure.lang.ILookup
(valAt [_ key])))

Instead it simply ignores that parameter in the method body in favour of clojure.core/key.

[CLJ-713] Upgrade ASM to a more current version

Mon, 11 Mar 2013 15:43:51 -0500

Move to the latest ASM (currently 3.3.1)
No longer subset-ed
Still re-rooted it under clojure.asm

[CLJ-250] debug builds

Thu, 14 Mar 2013 13:28:51 -0500

This ticket includes two patches:

a patch to set assert when clojure.lang.RT loads, based on the presence of system property clojure.debug
expand error messages in assert to include local-bindings</code> (a new macro which wraps the implicit <code>&env)

Things to consider before approving these patches:

should there be an easy Clojure-level way to query if debug is enabled? (checking assert isn't the same, as debug should eventually drive other features)
assertions will now be off by default – this is a change!
is the addition of the name local-bindings to clojure.core cool?

[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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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-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.

[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-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-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-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-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-445] Method/Constructor resolution does not factor in widening conversion of primitive args

Mon, 20 Feb 2012 14:04:42 -0600

Problem:
When making java calls (or inlined functions), if both args and param are primitive, no widening conversion is used to locate the proper overloaded method/constructor.

Examples:

user=> (Integer. (byte 0))
java.lang.IllegalArgumentException: No matching ctor found for class java.lang.Integer (NO_SOURCE_FILE:0)
</code></pre>
The above occurs because there is no Integer(byte) constructor, though it should match on Integer(int).
<pre><code>user=> (bit-shift-left (byte 1) 1)
Reflection warning, NO_SOURCE_PATH:3 - call to shiftLeft can't be resolved.
2

In the above, a call is made via reflection to Numbers.shiftLeft(Object, Object) and its associated auto-boxing, instead of directly to the perfectly adequate Numbers.shiftLeft(long, int).

Workarounds:
Explicitly casting to the formal type.

Ancillary benefits of fixing:
It would also reduce the amount of method overloading, e.g., RT.intCast(char), intCast(byte), intCast(short), could all be removed, since such calls would pass to RT.intCast(int).

[CLJ-862] pmap level of parallelism inconsistent for chunked vs non-chunked input

Sat, 20 Oct 2012 00:45:48 -0500

The code of pmap creates futures for the set of map operations it needs to perform with (map #(future %) coll), then acts on that sequence in a fashion obviously intended to keep only #CPUs+2 unfinished futures realized at any given time. It works exactly this way for non-chunked input seqs, but when pmap is passed a chunked seq, the seq of futures also becomes chunked. This causes an arbitrary number of futures to be realized as the #CPUs+2 window and chunk-size window interact.

The doc-string for pmap doesn't promise any particular level of parallelism, but I think the inconsistent parallelism for chunked vs non-chunked input comprises a bug.

[CLJ-891] make (symbol foo "bar") work with foo being a namespace

Fri, 2 Mar 2012 16:53:07 -0600

I've run across the need to do (symbol ns "bar") a few times, and the existing approach (symbol (name (ns-name ns)) "bar") just doesn't seem like it ought to be the only way to do the job. Includes a patch to make this work, by adding a new arity to Symbol.intern().

Some discussion on this idea, here: https://groups.google.com/forum/#!topic/clojure/n25aZ5HA7hc/discussion

[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-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-944] (.containsKey {:one 1} :one) throws Exception

Sat, 13 Apr 2013 12:06:35 -0500

Patch clj944-plus-tests does three things:

includes the previous "0002" patch which has the compiler emit map types consistent with the reader
adds tests
removes tests that were broken all along and now symptomatic

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-1161] sources jar has bad versions.properties resource

Fri, 12 Apr 2013 09:36:58 -0500

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-1018] range's behavior is inconsistent

Fri, 12 Apr 2013 09:59:12 -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-949] let undeclared exceptions continue unchecked

Fri, 1 Mar 2013 09:37:59 -0600

The recent modifications regarding checked exceptions have eliminated the need for several try/catch blocks. This commit removes the blocks that no longer serve a purpose.

[CLJ-1160] reducers/mapcat ignores Reduced

Fri, 1 Mar 2013 09:40:09 -0600

The following code throws an exception:

(->> (concat (range 100) (lazy-seq (throw (Exception. "Too eager"))))
(r/mapcat (juxt inc str))
(r/take 5)
(into []))

This is because r/mapcat introduces an intermediate reduce which swallows the reduced value coming from r/take.

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

Fri, 12 Apr 2013 09:42:02 -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

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

Fri, 12 Apr 2013 09:52:25 -0500

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-827] unsigned-bit-shift-right

Fri, 12 Apr 2013 09:52:24 -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-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-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-1125] Clojure can leak memory when used in a servlet container

Mon, 13 May 2013 19:30:16 -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-322] Enhance AOT compilation process to emit classfiles only for explicitly-specified namespaces

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

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-394] Add marker Interfaces for defrecords and deftypes plus boolean test fns

Fri, 1 Mar 2013 09:41:09 -0600

Sometimes one would like to know if an object is an instance of a deftype or a defrecord.
Add (possibly empty) marker Interfaces that allow an efficient test, plus test fns
'record?' and 'deftype?'.

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

Fri, 1 Mar 2013 09:47:45 -0600

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-858] Improve speed of STM by removing System.currentTimeMillis

Fri, 1 Mar 2013 09:41:33 -0600

Original post: https://groups.google.com/d/topic/clojure/kc99LcUK8Tk/discussion

This patch removes the milliseconds from inner class TVal in LockingTransaction.java and Ref.java. Using a little test suite[1] a increase of performance by up to 25% could be measured.

If necessary I can recreate the patch against current MASTER.

References:
[1] https://github.com/ska2342/clj-stm-perf-test/

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

Fri, 12 Apr 2013 09:42:00 -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-1187] Clojure loses quoted metdata on empty literals

Fri, 12 Apr 2013 09:42:02 -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-908] Functions with metadata print poorly

Fri, 12 Apr 2013 10:00:30 -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-896] Make browse-url aware of xdg-open

Fri, 12 Apr 2013 10:01:31 -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-873] Allow the function / to be referred to in namespaces other than clojure.core

Fri, 12 Apr 2013 10:04:21 -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-783] clojure.inspector/inspect-tree doesn't work on sets --patch in the description by Jason Wolfe

Fri, 12 Apr 2013 10:04:52 -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-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-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-1099] better error message when passing non-seq to seq

Fri, 12 Apr 2013 11:36:35 -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-1101] default-data-reader-fn should be set!-able in REPL

Sat, 13 Apr 2013 09:36:37 -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-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-1121] -> and ->> have unexpected behavior when combined with unusual macros

Fri, 12 Apr 2013 09:52:24 -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-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-1176] clojure.repl/source fails when read-eval bound to :unknown

Sat, 4 May 2013 22:40:43 -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-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-1175] NPE in clojure.lang.Delay/deref

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

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.

So I've attached a patch that causes Delay to rethrow the original exception, and a test for that behavior, which of course fails if the change to Delay is not made.

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

Fri, 17 May 2013 09:04:31 -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-1193] bigint, biginteger throw on double values outside of long range

Fri, 17 May 2013 10:52:24 -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-1072] Replace old metadata reader macro syntax

Fri, 12 Apr 2013 08:13:37 -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-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-863] interleave should accept 1 or 0 arguments

Fri, 12 Apr 2013 10:03:08 -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-1143] Minor correction to doc string of ns macro

Fri, 10 May 2013 12:30:41 -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-1164] typos in instant.clj

Fri, 10 May 2013 12:48:26 -0500

There are a few typographical mistakes in instant.clj.

[CLJ-1001] Proxy cannot call proper super-class method

Wed, 23 May 2012 22:24:43 -0500

Attached is a program that reproduces this issue. We have a proxy, `p', which sub-classes java.io.InputStream. There are three methods named `read' in java.io.InputStream: abstract int read(); int read(byte[] b); and int read(byte[] b, int off, int len); see http://docs.oracle.com/javase/6/docs/api/java/io/InputStream.html. In the definition of proxy `p', we implement the abstract variant of method `read', making `p' a concrete instance of java.io.InputStream.

The first invocation, (. p read), returns -1, which is expected.

The second invocation, (. p (read b 0 n)), should call int read(byte[] b, int off, int len); in java.io.InputStream. But these are actual behavior:

$ clojure1.2 ~/tmp/proxy-bug.clj
Exception in thread "main" java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn (proxy-bug.clj:0)
at clojure.lang.Compiler.eval(Compiler.java:5441)
at clojure.lang.Compiler.load(Compiler.java:5858)
at clojure.lang.Compiler.loadFile(Compiler.java:5821)
at clojure.main$load_script.invoke(main.clj:221)
at clojure.main$script_opt.invoke(main.clj:273)
at clojure.main$main.doInvoke(main.clj:354)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.lang.Var.invoke(Var.java:365)
at clojure.lang.AFn.applyToHelper(AFn.java:161)
at clojure.lang.Var.applyTo(Var.java:482)
at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Wrong number of args (4) passed to: user$eval1$fn
at clojure.lang.AFn.throwArity(AFn.java:437)
at clojure.lang.AFn.invoke(AFn.java:51)
at user.proxy$java.io.InputStream$0.read(Unknown Source)
at user$eval1.invoke(proxy-bug.clj:9)
at clojure.lang.Compiler.eval(Compiler.java:5425)
... 10 more

[CLJ-740] Unnecessary boxing of primitives in case form

Tue, 1 Mar 2011 02:51:43 -0600

Found this while profiling some performance-critical code.

Consider the following Clojure function:

(defn test-case ^double [^long i ^double d1 ^double d2]
  (case (int i)
    0 d1
    d2))

Current Clojure 1.3 snapshot compiles it to:

public final double invokePrim(long, double, double)   throws java.lang.Exception;
  Code:
   0:	lload_1
   1:	invokestatic	#67; //Method clojure/lang/RT.intCast:(J)I
   4:	istore	7
   6:	iload	7
   8:	i2l
   9:	invokestatic	#73; //Method clojure/lang/Numbers.num:(J)Ljava/lang/Number;
   12:	invokestatic	#79; //Method clojure/lang/Util.hash:(Ljava/lang/Object;)I
   15:	iconst_0
   16:	ishr
   17:	iconst_1
   18:	iand
   19:	tableswitch{ //0 to 0
		0: 36;
		default: 58 }
   36:	iload	7
   38:	i2l
   39:	invokestatic	#73; //Method clojure/lang/Numbers.num:(J)Ljava/lang/Number;
   42:	getstatic	#45; //Field const__3:Ljava/lang/Object;
   45:	invokestatic	#83; //Method clojure/lang/Util.equals:(Ljava/lang/Object;Ljava/lang/Object;)Z
   48:	ifeq	58
   51:	dload_3
   52:	invokestatic	#88; //Method java/lang/Double.valueOf:(D)Ljava/lang/Double;
   55:	goto	63
   58:	dload	5
   60:	invokestatic	#88; //Method java/lang/Double.valueOf:(D)Ljava/lang/Double;
   63:	checkcast	#92; //class java/lang/Number
   66:	invokevirtual	#96; //Method java/lang/Number.doubleValue:()D
   69:	dreturn
}

This bytecode contains boxing of primitives (calls to clojure/lang/Numbers.num and java/lang/Double.valueOf) and calls to clojure/lang/Util.hash and clojure/lang/Util.equals that does not seem necessary.

At 60-66 primitive double is boxed into Double only to be converted back into primitive.

The equivalent Java code compiles to much simpler and faster bytecode:

public double testCase(long, double, double);
  Code:
   0:	lload_1
   1:	l2i
   2:	lookupswitch{ //1
		0: 20;
		default: 22 }
   20:	dload_3
   21:	dreturn
   22:	dload	5
   24:	dreturn
}

[CLJ-760] ClassNotFound when AOT compiling a self-referring deftype extended to a protocol

Fri, 18 Mar 2011 10:27:46 -0500

If I create a deftype that refers to itself in a protocol extension like below:

(ns type-test)

(defprotocol Foo
  (isa-foo [x]))

(deftype TypeTest []
  Foo
  (isa-foo [x]
           (instance? TypeTest x)))

And use that code via another namespace:

(ns test-type-user
  (:use [type-test :only (isa-foo)])
  (:import [type-test TypeTest]))

(isa-foo (TypeTest.))

When I try to AOT compile the test-type-user namespace with Clojure 1.2.0, I get java.lang.NoClassDefFoundError: compilestub/type-test/TypeTest (test_type_user.clj:5). Full stack trace attached. Running the same code on 1.2.1 and 1.3.0-alpha6 yielded the same exception with a slightly different error message (stacktrace for 1.2.1 is also in the attached file).

This came up in a test at Revelytix. We worked around this issue by not using instance? and instead comparing based on class name. Another workaround is to define the deftype and the extension separately (using extend-type or something similar). This problem also doesn't occur if the usage of the deftype and the definition of it are in the same namespace (i.e. if type-test and test-type-user were in the same file).

[CLJ-864] defrecord positional arity factory fn should have an inline version that calls the record constructor

Wed, 26 Oct 2011 03:17:55 -0500

defrecord positional arity factory fn should have an inline version that calls the record constructor

[CLJ-1046] Drop-while as a reducer

Sat, 18 Aug 2012 19:11:59 -0500

Implement drop-while as a reducer. Follows the same atom-based strategy as drop and take.

Does not depend on any of my other reducer patches, but there will probably be some minor merge conflicts unless it is merged after CLJ-1045, and before CLJ-992 and CLJ-993.

[CLJ-887] Error when calling primitive functions with destructuring in the arg vector

Tue, 29 Nov 2011 15:48:19 -0600

If one defines a primitive-taking function with destructuring, calling that function will result in a ClassCastException, IFF the primitive return-type hint is present.

Clojure 1.4.0-master-SNAPSHOT
user=> (defn foo [[a b] ^long x ^long y] 0)
#'user/foo
user=> (foo [1 2] 3 4)
0
user=> (defn foo ^long [[a b] ^long x ^long y] 0)
#'user/foo
user=> (foo [1 2] 3 4)
ClassCastException user$foo cannot be cast to clojure.lang.IFn$OLLL  user/eval9 (NO_SOURCE_FILE:4)
user=> (pst)
ClassCastException user$foo cannot be cast to clojure.lang.IFn$OLLL
	user/eval9 (NO_SOURCE_FILE:4)
	clojure.lang.Compiler.eval (Compiler.java:6493)
	clojure.lang.Compiler.eval (Compiler.java:6459)
	clojure.core/eval (core.clj:2796)
	clojure.main/repl/read-eval-print--5967 (main.clj:244)
	clojure.main/repl/fn--5972 (main.clj:265)
	clojure.main/repl (main.clj:265)
	clojure.main/repl-opt (main.clj:331)
	clojure.main/main (main.clj:427)
	clojure.lang.Var.invoke (Var.java:397)
	clojure.lang.Var.applyTo (Var.java:518)
	clojure.main.main (main.java:37)
nil

[CLJ-884] Reflector error messages can be improved when no matching method is found.

Fri, 23 Mar 2012 01:14:18 -0500

When accessing a java method with an arity mismatch or a mismatched parameter type, Reflector.java returns the following error on REPL:
IllegalArgumentException No matching method found: xyz for class com.abc.MyClass

eventhough method xyz might exist on MyClass, but was being called with the wrong number of arguments.

Attached is a patch that fixes that problem.

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

Mon, 27 Aug 2012 21:24:13 -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-959] after call to clojure.java.shell/sh, jvm won't exit

Fri, 8 Jun 2012 12:47:07 -0500

Create the following four-line file, shell_example.clj:

;; simple example of call to sh that causes jvm to hang after print
(require '[clojure.java.shell :as shell])
(shell/sh "ls")
(println "jvm should exit after this, but it doesn't")

Run:
java -jar clojure-1.3.0.jar shell_example.clj

After the message is printed, the jvm doesn't quit. It just sits there. I have to hit Ctrl-C to force the jvm to quit.

This happens on 1.3 and the most recent code in github as of 3/26/2012. I imagine the jvm is waiting for a thread that hasn't terminated, but the code in the sh function doesn't look like it's doing anything obviously wrong. I'm too much of a newcomer to Clojure to dig any deeper.

My workaround right now is to do (System/exit 0) to force the jvm to quit.

Thank you for your work on Clojure, it's simply an amazing language.

[CLJ-1013] Clojure's classloader cannot handle out-of-order loading

Wed, 13 Jun 2012 15:21:42 -0500

Here is a minimal test-case:

import java.io.IOException;

import clojure.lang.PersistentTreeMap;
import clojure.lang.RT;

public class TestClass {

static Class y = RT.class;
//static PersistentTreeMap x = PersistentTreeMap.EMPTY;

/**

@param args
@throws ClassNotFoundException
@throws IOException
*/
public static void main(String[] args) throws IOException, ClassNotFoundException { PersistentTreeMap x = PersistentTreeMap.EMPTY; }

}

This results in the exception:

Exception in thread "main" java.lang.ExceptionInInitializerError
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at clojure.lang.RT.loadClassForName(RT.java:2056)
at clojure.lang.RT.load(RT.java:419)
at clojure.lang.RT.load(RT.java:400)
at clojure.lang.RT.doInit(RT.java:436)
at clojure.lang.RT.<clinit>(RT.java:318)
at clojure.lang.PersistentTreeMap.<init>(PersistentTreeMap.java:45)
at clojure.lang.PersistentTreeMap.<clinit>(PersistentTreeMap.java:32)
at TestClass.main(TestClass.java:19)
Caused by: java.lang.NullPointerException
at clojure.lang.APersistentSet.contains(APersistentSet.java:33)
at clojure.lang.RT.contains(RT.java:700)
at clojure.core$contains_QMARK_.invoke(core.clj:1386)
at clojure.core$load_lib.doInvoke(core.clj:5255)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invoke(core.clj:603)
at clojure.core$load_libs.doInvoke(core.clj:5298)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invoke(core.clj:603)
at clojure.core$require.doInvoke(core.clj:5381)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core__init.load(Unknown Source)
at clojure.core__init.<clinit>(Unknown Source)
... 10 more

The crux of the issue appears Clojure's classloader doesn't understand how to handle out-of-order classloading.

[CLJ-968] ns emitting gen-class before imports results in imported annotations being discarded.

Mon, 9 Apr 2012 15:38:07 -0500

The following discards the imported annotations:

(ns com.example.BaseXModuleTest
  (:import (org.basex.query QueryModule QueryModule$Deterministic))
  (:gen-class
     :extends org.basex.query.QueryModule
     :methods [
       [^{QueryModule$Deterministic {}}
        addOne [int] int]]))

However, when moving the gen-class call out of the ns declaration, the annotation is correctly applied:

(ns com.example.BaseXModuleTest
  (:import (org.basex.query QueryModule QueryModule$Deterministic)))

(gen-class
  :extends org.basex.query.QueryModule
  :name com.example.BaseXModuleTest
  :methods [
    [^{QueryModule$Deterministic {}}
     addOne [int] int]])

It appears that imported names are not yet in-scope when gen-class is run from a ns declaration.

[CLJ-969] Symbol/keyword implements IFn for lookup but a non-collection argument produces non-intuitive results

Mon, 9 Apr 2012 17:29:03 -0500

('+ 1 2) ;; return 2 because it is treated as (get 1 '+ 2)

Whilst this is "consistent" once you know the lookup behavior, it's confusing for Clojure newbies and it seems to be a non-useful behavior.

Proposal: modify Keyword.invoke() and Symbol.invoke() to restrict first Object argument to instanceof ILookup, Map or IPersistentSet (or null) so that the "not found" behavior doesn't produce non-intuitive behavior.

[CLJ-971] Jar within a jar throws a runtime error

Tue, 10 Apr 2012 22:39:36 -0500

I've created two jar files in my multi-project Maven setup. The first jar is the "engine", and it includes the clojure jar in it. The other jar is the "application". It includes the engine and then packages itself into a one-jar jar file. This means we have a jar within a jar: The "onejar" contains the engine jar, which in turn contains that clojure jar.

I then get an error in the runtime:

Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.simontuffs.onejar.Boot.run(Boot.java:340)
at com.simontuffs.onejar.Boot.main(Boot.java:166)
Caused by: java.lang.ExceptionInInitializerError
at com.ziroby.clojure.App.main(App.java:14)
... 6 more
Caused by: java.lang.NullPointerException
at clojure.lang.RT.lastModified(RT.java:374)
at clojure.lang.RT.load(RT.java:408)
at clojure.lang.RT.load(RT.java:398)
at clojure.lang.RT.doInit(RT.java:434)
at clojure.lang.RT.<clinit>(RT.java:316)
... 7 more

See also my Stack Overflow question on this at http://stackoverflow.com/questions/7763480/making-an-executable-jar-that-evals-clojure-strings

In researching it, I've found the problem lies in RT.lastModified, where it tries to determine last modified time by looking at the modified time on the jar file for Clojure. But there's not actually a jar file, since it's embedded in another.

I've found that adding a null check solves the problem. My lastModified looks like this now:

static public long lastModified(URL url, String libfile) throws Exception{
if(url.getProtocol().equals("jar")) { ZipEntry entry = ((JarURLConnection) url.openConnection()).getJarFile().getEntry(libfile); if (entry != null) return entry.getTime(); }

return url.openConnection().getLastModified();
}

This runs successfully.

If you'd prefer, I can submit a patch, or commit directly.

[CLJ-903] extend-protocol does not allow classnames as a String

Fri, 30 Dec 2011 17:17:12 -0600

In various places Clojure accepts classnames as String, eg. in gen-class or type hints. However it does not in extend-protocol. This does not allow simple specification of array types.

[CLJ-1022] gen-class destroys method annotations

Tue, 3 Jul 2012 06:19:26 -0500

When extending a class gen-class doesn't preserve method annotations.

If class com.bar.Foo has annotated methods then in MyClass all annotations are gone.

(gen-class
:name com.my.MyClass
:extends com.bar.Foo
:implements [com.google.common.base.Supplier]
:prefix demo-
:post-init post-init)

(defn demo-post-init [this]
(info "initialized")
(swank.swank/start-server :port 68478))

(defn demo-get [_]
(get-msg))

Class<?> aClass = Class.forName("com.my.MyClass");
Method[] methods = aClass.getMethods();

for (Method m : methods) {
Annotation[] annotations = m.getAnnotations();
System.out.println(m.getName()+" "+annotations.length);
for (Annotation a : annotations) { System.out.println(a.annotationType().getClass().getName()); }
}

[CLJ-911] 'proxy' prevents overriding Object.finalize (and doesn't document it)

Mon, 16 Jan 2012 08:36:27 -0600

It appears to be impossible to override Object.finalize() using proxy. If the method is defined using proxy, then it cannot be called straightforwardly (see below), and it is not called as a finalizer during normal program execution (not demonstrated below).

See extensive discussion at: https://groups.google.com/group/clojure/browse_thread/thread/a1e2fca45af6c1af

user=> (def m (proxy [java.util.HashMap] []
(finalize []
;(proxy-super finalize)
(prn "finalizing..."))
(hashCode []
99)))
#'user/m
user=> (.hashCode m)
99
user=> (.finalize m)
IllegalArgumentException No matching field found: finalize for class user.proxy$java.util.HashMap$0 clojure.lang.Reflector.getInstanceField (Reflector.java:289)

There is at least one of two bugs here (thanks to Cedric Greevey for summarising this way):

If the inability to override finalize() is unintentional, that's a bug.
If it's intentional for some reason, then (a) that's not documented, and (b) the failure is silent, in the sense that an explicit call produces an apparently completely unrelated error (above), and the failure to call the method during object finalization is completely silent.

[CLJ-1037] Allow doc strings for both interfaces and concrete implementations

Sat, 4 Aug 2012 10:30:53 -0500

In this post
http://groups.google.com/group/clojure/browse_thread/thread/84de74740928da76#

I mentioned the rationale (I think) why this is important and needed. Thank you for consideration.

[CLJ-986] Adds an exit function to exit clojure process

Sun, 6 May 2012 21:25:57 -0500

There is no standard function to exit the clojure process.
In java implementation,we use (System/exit 0),but in other implementations(CLR), i have to use another function.

Why not add a standard function in clojure.core?
For example:

(defn exit
([] (exit 0)
([status] (System/exit status)))

I think it's useful for us.

[CLJ-919] cannot create anonymous primitive functions

Fri, 27 Jan 2012 16:48:42 -0600

Primitive functions only work (e.g. return primitive types) when defined with `defn`. An equivalent function created with `fn` does not behave the same way as when created with `defn`. For example:

(definterface IPrimitiveTester
(getType [^int x])
(getType [^long x])
(getType [^float x])
(getType [^double x])
(getType [^Object x]))

(deftype PrimitiveTester []
IPrimitiveTester
(getType [this ^int x] :int)
(getType [this ^long x] :long)
(getType [this ^float x] :float)
(getType [this ^double x] :double)
(getType [this ^Object x] :object))

(defmacro pt [x]
`(.getType (PrimitiveTester.) ~x))

(defn with-defn ^double [^double x]
(+ x 0.5))

(pt (with-defn 1.0)) ; => :double

(let [a (fn ^double [^double x] (+ x 0.5))]
(pt (a 0.1))) ; => :object

Please see the discussion on the mailing list for more details and thoughts on what is happening:
http://groups.google.com/group/clojure/browse_thread/thread/d83c8643a7c7d595?hl=en

[CLJ-979] map->R returns different class when invoked from AOT ccode

Sun, 13 May 2012 22:35:35 -0500

(defrecord Dontwork [a])

(= (type (Dontwork. nil))
(type (map->Dontwork {:a 1})))

Will return true if the namespace is not AOT compiled and false if it is.

I have created a small example project with AOT and non-AOT namespaces to demonstrate
https://github.com/ejackson/aotquestion

[CLJ-792] Refactor method resolution code out of Compiler and into Reflector

Mon, 20 Feb 2012 13:11:06 -0600

Issues:

Code for obtaining method/constructor instances is duplicated across the Compiler
Code for resolving a preferred overloaded method lives in the Compiler

By consolidating the duplicated code, moving the reflection-related parts into Reflector, and providing a straightforward API, it should be easier to read and understand the method resolution process. Further, improvements to (e.g., CLJ-445) the mechanism for reflecting on class members can largely be isolated from the Compiler. And the few points of coordination (e.g., Compiler emitting same arg and return types as Reflector does when invoking) can be clearly identified and documented.

[CLJ-994] repeat reducer

Fri, 14 Sep 2012 14:37:35 -0500

i'm working on clojure.core/repeat reducer.

[CLJ-995] sorted-set doesn't support IEditableCollection

Mon, 4 Jun 2012 02:32:56 -0500

I think sorted-set (PersistentTreeSet) should implement the transient interface. It's a special-purpose set and should be usable just like every normal set.

[CLJ-1081] REPL binding not working that works with with-bindings

Mon, 1 Oct 2012 05:51:46 -0500

This works as expected:

java -jar clojure-1.4.0.jar -e "(do (require 'clojure.repl) (.setDynamic #'clojure.repl/print-doc) (with-bindings {#'clojure.repl/print-doc str} (eval '(clojure.repl/doc println))))"

Output:

"{:ns #<Namespace clojure.core>, :name println, :arglists ([& more]), :added \"1.0\", :static true, :doc \"Same as print followed by (newline)\", :line 3325, :file \"clojure/core.clj\"}"

But the same thing does not work in the REPL:

java -jar clojure-1.4.0.jar -e "(do (require 'clojure.repl) (.setDynamic #'clojure.repl/print-doc) (clojure.main/repl :init (fn [] {#'clojure.repl/print-doc str}))))"

Output for Output of {{(doc println)}}:

user=> (doc println)
-------------------------
clojure.core/println
([& more])
Same as print followed by (newline)
nil
user=>

[CLJ-1077] thread-bound? returns true (implying set! should succeed) even for non-binding thread

Mon, 1 Oct 2012 11:57:10 -0500

thread-bound? returns true for a non-binding thread, this result (according to the docstring) implies that set! should succeed. However, thread-bound? does not check that any binding that might exist was created by the current thread, and calling set! fails with an exception when it is called from a non-binding thread, even though thread-bound? returns true.

thread-bound? should return false if there is a binding, and that binding was not established by the current thread.

[CLJ-790] Primitive type hints on function names should print error message

Tue, 10 May 2011 12:11:37 -0500

Functions returning primitives are hinted with metadata on the argument list, not on the function name. Using a primitive type hint on a function name should print an error message.

Currently, misplaced primitive hints are read without error.

[CLJ-992] `iterate` reducer

Fri, 12 Oct 2012 08:10:52 -0500

Added a reducer implementation mirroring clojure.core/iterate.

[CLJ-993] `range` reducer

Sat, 18 Aug 2012 19:18:48 -0500

Rich mentioned in IRC today he'd welcome a reducer implementation of clojure.core/range. Now that I've figured out how to do iterate, I figure I'll knock out range as well by the end of the night. Just opening the issue early to announce my intentions to anyone else interested in doing it.

[CLJ-1059] PersistentQueue doesn't implement java.util.List, causing nontransitive equality

Tue, 11 Dec 2012 13:58:01 -0600

PersistentQueue implements Sequential but doesn't implement java.util.List. Lists form an equality partition, as do Sequentials. This means that you can end up with nontransitive equality:

(def q (conj clojure.lang.PersistentQueue/EMPTY 1 2 3))
;=> #user/q
(def al (doto (java.util.ArrayList.) (.add 1) (.add 2) (.add 3)))
;=> #user/al
(def v [1 2 3])
;=> #user/v
(= al v)
;=> true
(= v q)
;=> true
(not= al q)
;=> true

This happens because PersistentQueue is a Sequential but not a List, ArrayList is a List but not a Sequential, and PersistentVector is both.

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

Sat, 15 Dec 2012 07:50:03 -0600

If there is an error in the `ns` form, an exception is thrown, which is not caught in `load`.

For example, with an invalid :only clause;

(ns clj14.myns
  (:use
   [clojure.core :only seq]))

This generates a Don't know how to create ISeq from: clojure.lang.Symbol exception, with source file or line number.

[CLJ-899] Accept and ignore colon between key and value in map literals

Wed, 19 Dec 2012 07:55:59 -0600

Original title was 'treat colons as whitespace' which isn't a problem description but a (flawed) implementation approach

For JSON compatibility
known problems when no spaces - x:true and y:false

[CLJ-1136] Type hinting for array classes does not work in binding forms

Fri, 21 Dec 2012 11:09:56 -0600

Type hints don't work as expected in binding forms.

The following form results in a reflection warning:

(let [^{:tag (Class/forName "[Ljava.lang.Object;")} a (make-array Object 2)]
(aget a 0))

However, hinting does appear to work correctly on vars:

(def ^{:tag (Class/forName "[Ljava.lang.Object;")} a (make-array Object 2))
(aget a 0) ;; no reflection warning

[CLJ-1108] Allow to specify an Executor instance to be used with future-call

Thu, 27 Dec 2012 02:25:43 -0600

This adds an arity to future-call that expects a java.util.concurrent/ExecutorService instance to be used instead of clojure.lang.Agent/soloExecutor.

[CLJ-1142] Incorrect divide-by-zero error with floating point numbers

Tue, 8 Jan 2013 23:22:50 -0600

The unary call for clojure.core// treats a dividend of 0.0 differently than the binary call, likely due to inlining.

(/ 0.0) ;; java.lang.ArithmeticException: Divide by zero
(/ 1 0.0) ;;= Infinity
(/ 1 (identity 0.0)) ;; java.lang.ArithmeticException: Divide by zero

[CLJ-840] Add a way to access the current test var in :each fixtures for clojure.test

Fri, 18 Jan 2013 09:47:53 -0600

When looking at (log) output from tests written with clojure.test, I would like to be able to identify the output associated with each test. A mechanism to expose the current test var within an :each fixture would enable this.

One mechanism might be to bind a test-var var with the current test var before calling the each-fixture-fn in clojure.test/test-all-vars.

[CLJ-825] Protocol implementation inconsistencies

Mon, 8 Aug 2011 12:35:38 -0500

There seems to be some inconsistencies when implementing protocols that have multi arity functions depending on how the protocol is implemented. I have attached a clj file illustrating this. The short version is that multi arity must be defined as such w/ defrecord:

(defrecord Zomg []
SomeProto
(hello [_] 1)
(hello [_ _] 1))

And as such with extend-type

(extend-type Object
SomeProto
(hello
([_] 1)
([_ _] 1)))

I have only tested defrecord & extend-type. I am unsure how it works with deftype and extend-protocol.

[CLJ-1045] Generalize/refactor implementation of PersistentVector/coll-fold

Fri, 25 Jan 2013 14:29:31 -0600

Vector currently contains a specialized implementation of the folding algorithm "split the collection in half until the pieces are small enough". The attached commit lifts out the general strategy so that it can be reused by other collection types amenable to splitting.

CLJ-993 depends on this patch, as it uses the new fold-by-halves function.

[CLJ-1096] Make destrucring emit direct keyword lookups

Sat, 26 Jan 2013 08:15:49 -0600

Currently associative destructuring emits calls to get. The attached patch modify desctruture to emit direct keyword lookups when possible.

Approved here https://groups.google.com/d/msg/clojure-dev/MaYcHQck8VA/nauMus4mzPgJ

[CLJ-978] bean unable to handle non-public classes

Thu, 29 Nov 2012 10:01:49 -0600

Take the following Java as an example:

public interface IFoo {
  String getBar();
}

class FooImpl {
  String getBar() { return "bar"; }
}

As presently implemented, (bean my-foo) tries to invoke the following:

(. #<Method public java.lang.String FooImpl.getBar> (invoke my-foo nil))

However, as FooImpl is not public, this fails:

java.lang.IllegalAccessException: Class clojure.core$bean$fn__1827$fn__1828 can not access a member of class FooImpl with modifiers "public"
 at sun.reflect.Reflection.ensureMemberAccess (Reflection.java:65)
    java.lang.reflect.Method.invoke (Method.java:588)
    clojure.core$bean$fn__1827$fn__1828.invoke (core_proxy.clj:382)
    clojure.core$bean$v__1832.invoke (core_proxy.clj:388)
    clojure.core$bean$fn__1838$thisfn__1839$fn__1840.invoke (core_proxy.clj:406)
    clojure.lang.LazySeq.sval (LazySeq.java:42)
    clojure.lang.LazySeq.seq (LazySeq.java:60)
    clojure.lang.RT.seq (RT.java:473)

However, the same thing succeeds if we call #<Method public java.lang.String Foo.getBar> rather than #<Method public java.lang.String FooImpl.getBar>.

[CLJ-1079] Don't squash explicit :line and :column metadata in the MetaReader

Thu, 7 Feb 2013 12:35:21 -0600

I have been experimenting with using cljx to produce Clojure and ClojureScript source from a single file. This has gone well so far, with the exception that, due to the way the source transformation works, all of the linebreaks and other formatting is gone from the output. There is an option to include the original :line metadata in the output though, like so:

;;This file autogenerated from 
;;
;;  src/cljx/com/foo/hosty.cljx
;;
^{:line 1} (ns com.foo.hosty)
^{:line 3} (defn ^{:clj true} system-hash [x] ^{:line 5} (System/identityHashCode x))

(Hopefully, such hackery won't be necessary in the future with sjacket or something like it...)

Unfortunately, when read in using a LineNumberingPushbackReader, code like this has its :line metadata squashed by the line numbers coming from that. A REPL-friendly example would be:

=> (meta (read (clojure.lang.LineNumberingPushbackReader.
                 (java.io.StringReader. "^{:line 66} ()"))))
{:line 1}
=> (meta (read (java.io.PushbackReader.
                 (java.io.StringReader. "^{:line 66} ()"))))
{:line 66}

The latter seems more correct to me (and is equivalent to read-string).

[CLJ-859] Built in dynamic vars don't have :dynamic metadata

Fri, 24 Feb 2012 12:41:31 -0600

I'm sure 'built in' is probably not the right term here, but I'm not sure what these are called.

I ran into this issue earlier today while fixing a bug in clojail. Built in vars, particularly ones listed here without a source link: http://clojure.github.com/clojure/clojure.core-api.html, do not have :dynamic metadata despite being dynamic. This includes *in*, *out*, and *err* among others. Here are some examples:

user=> (meta #'*err*)
{:ns #<Namespace clojure.core>, :name *err*, :added "1.0", :doc "A java.io.Writer object representing standard error for print operations.\n\n  Defaults to System/err, wrapped in a PrintWriter"}
user=> (meta #'*in*)
{:ns #<Namespace clojure.core>, :name *in*, :added "1.0", :doc "A java.io.Reader object representing standard input for read operations.\n\n  Defaults to System/in, wrapped in a LineNumberingPushbackReader"}
user=> (meta #'*out*)
{:ns #<Namespace clojure.core>, :name *out*, :added "1.0", :doc "A java.io.Writer object representing standard output for print operations.\n\n  Defaults to System/out, wrapped in an OutputStreamWriter", :tag java.io.Writer}
user=> (meta #'*ns*)
{:ns #<Namespace clojure.core>, :name *ns*, :added "1.0", :doc "A clojure.lang.Namespace object representing the current namespace.", :tag clojure.lang.Namespace}

[CLJ-1100] Reader literals cannot contain periods

Thu, 14 Feb 2013 15:04:53 -0600

The LispReader tries to read a record instead of a literal if the tag contains periods:

https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/LispReader.java#L1171

Which effectively means that reader tags cannot contain periods.
The EDN spec is unclear on this:

edn supports extensibility through a simple mechanism. # followed immediately by a symbol starting with an alphabetic character indicates that that symbol is a tag.

(issue opened: https://github.com/edn-format/edn/issues/39)

If periods are allowed, then the LispReader should first check to see if the tag is in *data-readers* and only then if not try to initialize a Java class.

I'm happy to write the patch if this behavior is what is desired.

[CLJ-705] Make sorted maps and sets implement j.u.SortedMap and SortedSet interfaces

Sat, 2 Jun 2012 14:29:11 -0500

Make sorted maps and sets implement j.u.SortedMap and SortedSet interfaces

[CLJ-1076] pprint tests fail on Windows, expecting \n

Sat, 2 Mar 2013 14:51:46 -0600

New pprint tests were committed recently, but they fail on Windows because the tests check for \n, while pprint seems to output \r\n. A log with the test failures is attached.

The first failing commit is https://github.com/clojure/clojure/commit/4ca0f7ea17888ba7ed56d2fde0bc2d6397e8e1c0

[CLJ-1180] defprotocol doesn't resolve tag classnames

Sun, 10 Mar 2013 17:56:10 -0500

defprotocol doesn't resolve tag classnames, this results in exceptions being thrown when the declared protocol uses as a tag an imported class that is not imported in the namespace that uses it.

user=> (import 'clojure.lang.ISeq)
clojure.lang.ISeq
user=> (defprotocol p (^ISeq f [_]))
p
user=> (ns x)
nil
x=> (defn x [y] (let [z (user/f y)] (inc z)))
CompilerException java.lang.IllegalArgumentException: Unable to resolve classname: ISeq, compiling:(NO_SOURCE_PATH:4:33)

[CLJ-1181] clojure.pprint/code-dispatch breaks on certain types of anonymous functions

Mon, 18 Mar 2013 17:40:31 -0500

(with-out-str 
  (with-pprint-dispatch code-dispatch 
                        (pp/pprint (read-string "(fn* [x] x)"))))

breaks because the format string here: https://github.com/clojure/clojure/blob/master/src/clj/clojure/pprint/dispatch.clj#L378 expects a sequence. In the case of (fn* [x] x) it is passed a symbol.

[CLJ-865] Macroexpansion discards &form metadata

Wed, 6 Jun 2012 17:29:38 -0500

As discussed in http://groups.google.com/group/clojure/browse_thread/thread/2690cb6ca0e8beb8 there is a "surprise factor" when type-hinting an expression that represents a macro, such as with (.length ^String (doto (identity "x") prn)). Here the doto macro discards the metadata on &form, causing a reflective lookup. This has the effect that while expressions representing function calls can be type-hinted, expressions representing macros in general cannot. The doto macro could be rewritten to respect its &form metadata, but doing this for every macro in existence would be tedious and error-prone. Instead, I propose a change to the compiler, to cause macroexpansion to hang onto the metadata automatically.

The first patch attached adds a test for the behavior I propose: this test fails. After applying the second patch, the test passes.

There are a couple points that merit further consideration before accepting my patch:

I'm not sure I actually got the Java code formatted correctly. My editor is not well-configured to get the clojure/core style right automatically.
My solution is to take the &form metadata, drop :line/:file keys, and then merge with the returned metadata, with &form taking precedence. I'm not sure whether this is the right approach in all cases, even though it works for :tag metadata.
I achieved this with a change to the compiler, which makes it fairly heavy-weight. It should be possible to instead adjust defmacro if changes to the compiler are not desirable. However, I believe this would involve substantially more work and be harder to test (for example, multiple arities complicate things). It seems nicer to treat the macroexpansion as a black box and then make metadata tweaks to the result, rather than modifying their actual defmacro code.
If a macro expands to something that is not an IObj, such as an Integer, then my patch silently discards the caller's metadata. Would it be better to throw an exception?

[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-1093] Empty record literals gets incorrectly evaluated to array-maps

Wed, 13 Mar 2013 14:04:29 -0500

before patch:
user=> (defrecord a [b])
user.a
user=> #user.a{}
{}

after patch:
user=> (defrecord a [b])
user.a
user=> #user.a{}
#user.a{:b nil}

[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-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.