[elephant-devel] Problem with Elephant and BTree access

[Robert L. Read]

This works for me under SBCL; please see the attached typescript.

I can't conjecture what the problem might be; is the script you show
below everything?
Are the packages changes somehow done in a visual environment and there
for not showing?
Try running through my script and let me know what the results are, if
this is still a problem for you.


On Thu, 2006-01-05 at 17:01 -0500, Waldo Rubinstein wrote:

> Hi,
> 
> I'm starting to use BTrees in elephant and am encountering a problem.  
> Basically, I added a BTree object to the root under a key named  
> "EDI-834-TAPES". I can retrieve the BTree object, but when I try to  
> access a BTree element (whether to read or write), I get an error.  
> See below:
> 
> CL-USER> (in-package ele)
> #<Package "ELEPHANT">
> ELE> (open-store "testdb")
> #<BDB-STORE-CONTROLLER #x8A5C816>
> ELE> (setf tapes (get-from-root "EDI-834-TAPES"))
> #<BTREE #x8A5805E>
> ELE> (get-value 1234 tapes)
> CL-USER> (in-package ele)
> #<Package "ELEPHANT">
> ELE> (open-store "testdb")
> #<BDB-STORE-CONTROLLER #x8A5C816>
> ELE> (setf tapes (get-from-root "EDI-834-TAPES"))
> #<BTREE #x8A5805E>
> ELE> (get-value 1234 tapes)
> 
> No applicable method for args:
> (1234 #<BTREE #x8A5805E>)
> to #<STANDARD-GENERIC-FUNCTION GET-VALUE #x84146AE>
>     [Condition of type SIMPLE-ERROR]
> 
> Restarts:
>    0: [ABORT-REQUEST] Abort handling SLIME request.
>    1: [ABORT-BREAK] Reset this process
>    2: [ABORT] Kill this process
> 
> Backtrace:
>    0: (#<CCL::STANDARD-KERNEL-METHOD NO-APPLICABLE-METHOD (T)>  
> #<STANDARD-GENERIC-FUNCTION GET-VALUE #x84146AE>)
>    1: (CCL::CALL-CHECK-REGS 'GET-VALUE)
> 
> Basically, the last statement (get-value) should return NIL since  
> there is not BTree element within the BTree object.
> 
> What am I doing wrong? I tried to "mimic" as close as possible the  
> steps in the Blog tutorial but keep getting to the same problem.
> 
> Thanks,
> Waldo
> _______________________________________________
> elephant-devel site list
> elephant-devel at common-lisp.net
> http://common-lisp.net/mailman/listinfo/elephant-devel
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;   printed 11 notes
#<PACKAGE "ELEPHANT-TESTS">
ELE-TESTS> (open-store "../tests/testdb")
#<BDB-STORE-CONTROLLER {A18C361}>
ELE-TESTS> (setq bt (make-btree))
#<BDB-BTREE {A3770B9}>
ELE-TESTS> (add-to-root "EDI-834-TAPES" bt)
#<BDB-BTREE {A3770B9}>
ELE-TESTS> (get-value 1234 tapes)
; Evaluation aborted
ELE-TESTS> (setf tapes (get-from-root "EDI-834-TAPES"))
; in: LAMBDA NIL
;     (SETF ELEPHANT-TESTS::TAPES (ELEPHANT:GET-FROM-ROOT "EDI-834-TAPES"))
; ==>
;   (SETQ ELEPHANT-TESTS::TAPES (ELEPHANT:GET-FROM-ROOT "EDI-834-TAPES"))
; 
; caught WARNING:
;   undefined variable: TAPES

; 
; caught WARNING:
;   This variable is undefined:
;     TAPES
; 
; compilation unit finished
;   caught 2 WARNING conditions
#<BDB-BTREE {A3770B9}>
ELE-TESTS> (get-value 1234 tapes)
NIL
NIL
ELE-TESTS> (open-store "../tests/testdb")
#<BDB-STORE-CONTROLLER {A5BA8F1}>
ELE-TESTS> (setf tapes (get-from-root "EDI-834-TAPES"))

; in: LAMBDA NIL
;     (SETF ELEPHANT-TESTS::TAPES (ELEPHANT:GET-FROM-ROOT "EDI-834-TAPES"))
; ==>
;   (SETQ ELEPHANT-TESTS::TAPES (ELEPHANT:GET-FROM-ROOT "EDI-834-TAPES"))
; 
; caught WARNING:
;   undefined variable: TAPES

; 
; caught WARNING:
;   This variable is undefined:
;     TAPES
; 
; compilation unit finished
;   caught 2 WARNING conditions
#<BDB-BTREE {A5D6AD9}>
ELE-TESTS> (get-value 1234 tapes)
NIL
NIL
ELE-TESTS>