problem with closure over &aux variable

Hi all,  I think this is a bug, but before I report it, I'll ask.  Am
I doing something wrong here?


(defun test1 (n)
  (labels ((up-from (low)
             (let ((start (1- low)))
               #'(lambda () (incf start)))))
    (map-into (make-list n) (up-from 3))))

(defun test2 (n)
  (labels ((up-from (low &aux (start (1- low)))
             #'(lambda () (incf start))))
    (map-into (make-list n) (up-from 3))))


Each should return a list of length n populated with the integers from
3 to n+2.  The only difference is that start is bound with let in
test1 and as an &aux variable in test2.  Here's what happens on LWM
5.1.2 OS X Intel.


CL-USER 1 > (test1 10)
(3 4 5 6 7 8 9 10 11 12)

CL-USER 2 > (test2 10)

Error: Bus error(10) [code 0] at 21E6B8F2
eax       56 ; ebx       56 ; ecx        0 ; edx FE26898E
esp 21E6B8CC ; ebp 21E6B8F8 ; esi        2 ; edi 21E6B8F2
  1 (abort) Return to level 0.
  2 Return to top loop level 0.

Type :b for backtrace, :c <option number> to proceed,  or :? for other options

CL-USER 3 : 1 >


Is the bug with me or LispWorks (or both ^_^)?
Thanks, //JT

Re: problem with closure over &aux variable

Yeah, this seems like a bug with &aux variables and labels and flet.
I don't have the same problem if I define up-from as a separate
function with either the let or &aux variable.  I'll file a bug
report.

On Fri, Aug 7, 2009 at 7:08 PM, Joshua TAYLOR<tayloj@cs.rpi.edu> wrote:
> Hi all,  I think this is a bug, but before I report it, I'll ask.  Am
> I doing something wrong here?
>
>
> (defun test1 (n)
>  (labels ((up-from (low)
>             (let ((start (1- low)))
>               #'(lambda () (incf start)))))
>    (map-into (make-list n) (up-from 3))))
>
> (defun test2 (n)
>  (labels ((up-from (low &aux (start (1- low)))
>             #'(lambda () (incf start))))
>    (map-into (make-list n) (up-from 3))))
>
>
> Each should return a list of length n populated with the integers from
> 3 to n+2.  The only difference is that start is bound with let in
> test1 and as an &aux variable in test2.  Here's what happens on LWM
> 5.1.2 OS X Intel.
>
>
> CL-USER 1 > (test1 10)
> (3 4 5 6 7 8 9 10 11 12)
>
> CL-USER 2 > (test2 10)
>
> Error: Bus error(10) [code 0] at 21E6B8F2
> eax       56 ; ebx       56 ; ecx        0 ; edx FE26898E
> esp 21E6B8CC ; ebp 21E6B8F8 ; esi        2 ; edi 21E6B8F2
>  1 (abort) Return to level 0.
>  2 Return to top loop level 0.
>
> Type :b for backtrace, :c <option number> to proceed,  or :? for other options
>
> CL-USER 3 : 1 >
>
>
> Is the bug with me or LispWorks (or both ^_^)?
> Thanks, //JT
>



-- 
=====================
Joshua Taylor
tayloj@cs.rpi.edu, jtaylor@alum.rpi.edu

"A lot of good things went down one time,
  back in the goodle days."
    John Hartford

Re: problem with closure over &aux variable

Joshua,

Using 5.1.1personal edition under XP by copying your code into the listener..

CL-USER 1 > (defun test1 (n)
 (labels ((up-from (low)
            (let ((start (1- low)))
              #'(lambda () (incf start)))))
   (map-into (make-list n) (up-from 3))))
TEST1

CL-USER 2 >
(test1 5)
(3 4 5 6 7)

CL-USER 3 >
(defun test2 (n)
 (labels ((up-from (low &aux (start (1- low)))
            #'(lambda () (incf start))))
   (map-into (make-list n) (up-from 3))))
TEST2

CL-USER 4 >
(test2 5)
(3 4 5 6 7)

CL-USER 5 >
(test1 10)
(3 4 5 6 7 8 9 10 11 12)

CL-USER 6 >
(test2 10)
(3 4 5 6 7 8 9 10 11 12)

The same test also passed on a mac.

Ian Whitlock

On Sat, Aug 8, 2009 at 12:27 AM, Joshua TAYLOR<tayloj@cs.rpi.edu> wrote:
>
> Yeah, this seems like a bug with &aux variables and labels and flet.
> I don't have the same problem if I define up-from as a separate
> function with either the let or &aux variable.  I'll file a bug
> report.
>
> On Fri, Aug 7, 2009 at 7:08 PM, Joshua TAYLOR<tayloj@cs.rpi.edu> wrote:
>> Hi all,  I think this is a bug, but before I report it, I'll ask.  Am
>> I doing something wrong here?
>>
>>
>> (defun test1 (n)
>>  (labels ((up-from (low)
>>             (let ((start (1- low)))
>>               #'(lambda () (incf start)))))
>>    (map-into (make-list n) (up-from 3))))
>>
>> (defun test2 (n)
>>  (labels ((up-from (low &aux (start (1- low)))
>>             #'(lambda () (incf start))))
>>    (map-into (make-list n) (up-from 3))))
>>
>>
>> Each should return a list of length n populated with the integers from
>> 3 to n+2.  The only difference is that start is bound with let in
>> test1 and as an &aux variable in test2.  Here's what happens on LWM
>> 5.1.2 OS X Intel.
>>
>>
>> CL-USER 1 > (test1 10)
>> (3 4 5 6 7 8 9 10 11 12)
>>
>> CL-USER 2 > (test2 10)
>>
>> Error: Bus error(10) [code 0] at 21E6B8F2
>> eax       56 ; ebx       56 ; ecx        0 ; edx FE26898E
>> esp 21E6B8CC ; ebp 21E6B8F8 ; esi        2 ; edi 21E6B8F2
>>  1 (abort) Return to level 0.
>>  2 Return to top loop level 0.
>>
>> Type :b for backtrace, :c <option number> to proceed,  or :? for other options
>>
>> CL-USER 3 : 1 >
>>
>>
>> Is the bug with me or LispWorks (or both ^_^)?
>> Thanks, //JT
>>
>
>
>
> --
> =====================
> Joshua Taylor
> tayloj@cs.rpi.edu, jtaylor@alum.rpi.edu
>
> "A lot of good things went down one time,
>  back in the goodle days."
>    John Hartford
>
>



-- 
Ian Whitlock