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[CLJ-1591] Symbol not being bound in namespace when name clashes with clojure.core Created: 14/Nov/14  Updated: 22/Nov/14

Status: Reopened
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6, Release 1.7
Fix Version/s: Release 1.7

Type: Defect Priority: Major
Reporter: Mike Anderson Assignee: Unassigned
Resolution: Unresolved Votes: 1
Labels: None

Approval: Vetted

 Description   

The following code fails (both in 1.6 and latest 1.7-alpha4):

user=> (ns foo)
nil
foo=>  (def inc inc)
WARNING: inc already refers to: #'clojure.core/inc in namespace: foo, being replaced by: #'foo/inc
#'foo/inc

;; Note inc is unbound at this point, which causes the exception below
foo=> inc
#<Unbound Unbound: #'foo/inc>
foo=> (ns bar)
nil
bar=> (require ['foo :refer ['inc]])
WARNING: inc already refers to: #'clojure.core/inc in namespace: bar, being replaced by: #'foo/inc
nil
bar=> (inc 8)

IllegalStateException Attempting to call unbound fn: #'foo/inc  clojure.lang.Var$Unbound.throwArity (Var.java:43)

Further investigation shows that foo/inc is unbound:

foo/inc
=> #<Unbound Unbound: #'foo/inc>

Further investigation also shows that replacing the (def inc inc) with almost anything else, e.g. (def inc dec), (def inc clojure.core/inc), or (def inc (fn [n] (+ n 1))), causes no exception (but the warnings remain).

I would expect:
a) foo/inc should be bound and have the same value as clojure.core/inc
b) No error when requiring foo/inc
c) bar/inc should be bound to foo/inc



 Comments   
Comment by Nicola Mometto [ 14/Nov/14 10:04 PM ]

The second error should be expected, the right syntax should be (require ['foo :refer ['inc]]) (note the leading quote before inc)

Comment by Mike Anderson [ 14/Nov/14 10:20 PM ]

Thanks for the catch Nicola - I've edited the description. Still get the same error however (just with a slightly different message)

Comment by Alex Miller [ 14/Nov/14 10:22 PM ]

See comment...

Comment by Mike Anderson [ 14/Nov/14 10:24 PM ]

@Alex what comment? Note that the error still occurs even with the right syntax....

Comment by Mike Anderson [ 14/Nov/14 10:26 PM ]

Appears to have been closed prematurely

Comment by Alex Miller [ 14/Nov/14 10:39 PM ]

I can't reproduce with the correct syntax:

Clojure 1.7.0-master-SNAPSHOT
user=> (ns foo)
nil
foo=> (def inc inc)
WARNING: inc already refers to: #'clojure.core/inc in namespace: foo, being replaced by: #'foo/inc
#'foo/inc
foo=> (ns bar)
nil
bar=> (require ['foo :refer ['inc]])
WARNING: inc already refers to: #'clojure.core/inc in namespace: bar, being replaced by: #'foo/inc
nil
Comment by Mike Anderson [ 14/Nov/14 10:55 PM ]

The problem is that the var is still unbound and causes e.g. the following error:

=> (foo/inc 8)
IllegalStateException Attempting to call unbound fn: #'foo/inc clojure.lang.Var$Unbound.throwArity (Var.java:43)

I don't think that should be expected - or am I missing something?

Comment by Alex Miller [ 14/Nov/14 10:57 PM ]

Ah, will take a look. But not right now.

Comment by Andy Fingerhut [ 15/Nov/14 1:09 PM ]

Updated the description with a few more details. The exception goes away if you do (def inc (fn [n] (+ n 1))) instead of (def inc inc), for example. The warnings remain.

Comment by Tom Crayford [ 20/Nov/14 11:07 AM ]

Unsure if this is the same issue (I think it might be?), but I reproduced the exact same error message with AOT compilation involved:

reproduced in this git repository: https://github.com/yeller/compiler_update_not_referenced_bug

clone it, run `lein do clean, uberjar, test`, and that error message will show up every time for me

Comment by Andy Fingerhut [ 20/Nov/14 5:43 PM ]

Mike, I think replacing (def inc inc) in your example with (def inc clojure.core/inc) should be considered as a reasonable workaround for this issue, unless you have some use case where you need to def inc to something that is not in clojure.core (and if so, why?)

The reason (def inc inc) behaves this way is, if not absolutely necessary, at least commonly used in Clojure programs to define recursive functions, e.g. (defn fib [n] (if (<= n 1) 1 (+ (fib (dec n)) (fib (- n 2))))), so that the occurrences of fib in the body are resolved to the fib being defined.

Comment by Alex Miller [ 22/Nov/14 9:05 AM ]

Moving to 1.7 until I can look at this more deeply.





[CLJ-1580] Transient collections should guarantee thread visibility Created: 05/Nov/14  Updated: 22/Nov/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: Release 1.7

Type: Defect Priority: Major
Reporter: Alex Miller Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: transient

Approval: Vetted

 Description   

With changes from CLJ-1498, transients are still thread isolated but may move between threads during their lifetime which introduces new concurrency concerns, namely visibility of changes across threads.






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