Topic: Load / Unload a lisp by routine

[Hangman]

So I was search'n the database and found the 'Call a lisp from within a lisp', and I was a wonder'n if it could be taken one step further.
I am interested in calling a lisp from within a lisp, but I want to load a lisp that is not currently loaded.
So, you run lisp 'A', and it will call lisp 'B', and if it is not loaded, load it then run it.

I'm think'n this has been discussed before, but I haven't come across it yet.

[Kerry]

something like

Code: [Select]

(IF (NOT (VL-SYMBOL-VALUE 'kg:build))
    (LOAD "KDUB_BaseLibrary" "Unable to LOAD 'KDUB_BaseLibrary.VLX' ")
    (PRINC)
)

[Hangman]

Yeah Kerry, someth'n like that.  Essept ... I don't wanna "Unable to LOAD ..."    I wanna "able to LOAD ..."
And what is the 'kg:build ??

[Kerry]

'kg:build is a global variable representing the build date of the file, it is set when 'KDUB_BaseLibrary.VLX' is loaded.

I think you mis-understand the LOAD function.
The "Unable to LOAD 'KDUB_BaseLibrary.VLX' " string is the message to display IF the LOAD routine fails .. ie if the file can't be found or is spacoid.
The LOAD routine is evaluated only if the variable is not set, ie if the file in question is not loaded.

 You can also test for the existance of one of the functions in memory defined in your file using the same methodology.

[Hangman]

'kg:build is a global variable representing the build date of the file, it is set when 'KDUB_BaseLibrary.VLX' is loaded.

I think you mis-understand the LOAD function.
The "Unable to LOAD 'KDUB_BaseLibrary.VLX' " string is the message to display IF the LOAD routine fails .. ie if the file can't be found or is spacoid.
The LOAD routine is evaluated only if the variable is not set, ie if the file in question is not loaded.

Aaaaa ...  makes sense.  Ok, then I need a 'VL-SYMBOL-VALUE' to search for my program, then, IF NOT found, to LOAD it.
How can I find out a VL-SYMBOL-VALUE like the kg:build ??  Where would I go to find that and what am I looking for (i.e.: date, serial #, etc) ??

[Kerry]

In the file in question I have something like this at the end ..
which is equivalent to SETQ'ing a variable as the file loads.

Code: [Select]

;;;------------------------------------------------------------------
;;;------------------------------------------------------------------
;;;
(kdub:defineconstant 'KG:build "20060521")

(prompt (strcat "\nKDUB_BaseLibrary V1.25.60521 [Build:" KG:build "]"))
;;;------------------------------------------------------------------
;;;------------------------------------------------------------------for completeness, this is my kdub:defineconstant routine ..

Code: [Select]

(defun KDUB:defineconstant (symbolname symbolvalue)
  (pragma '((unprotect-assign symbolname)))
  (set symbolname symbolvalue)
  (pragma '((protect-assign symbolname)))
  (princ)
);;;------------------------------------------------------------------
;;;------------------------------------------------------------------

[Tramber]

What does "pragma" mean ?

just curious

[Kerry]

Try this ..

http://groups.google.com/group/autodesk.autocad.customization/browse_thread/thread/2b84c3fa5862e7a0/43e03593a0577ac1?lnk=st&q=pragma+lisp&rnum=2&hl=en#43e03593a0577ac1


and, if memory serves, I think the use of pragma has been discussed a couple of times here.

added:
yep, just feed pragma to the site search engine ....

[Tramber]

and, if memory serves, I think the use of pragma has been discussed a couple of times here.

I know, but a very few times and with no explanation at all.

But you gave us a real good link and I finally understood.
That makes me think about a issue : I was wondering how we make our functions to turn blue, that is a way. But that's an other topic.

[Kerry]

Bert,
The code I posted will make the SymbolName protected, and therefore display Blue in the IDE,

[Tramber]

Yes, sure, I wanted to say :
Well, here is a way, is there another one ? 

Another question : is the quantity of functions we would like to protect critical ? According to U.

[Kerry]

.. and try something like this ..

Code: [Select]

(pragma '((unprotect-assign adderupper)))
;;
(DEFUN adderupper (var1 var2 /)
  (IF (AND NUMBERP var1)
    (AND NUMBERP var2)
  )
  (+ var1 var2)
)
;;
(pragma '((protect-assign adderupper)))
Piccy after loading the code

[Kerry]

Ahhh words and meanings ..
You probably know this Bert, but for others ..
protect in this case just means that the editor will warn you if an attempt is made to redefine the function .. nothing to do with security, despite the name ..

I Pragma protect ALL my library routine names and constant Global variable ... old habit I guess ... but not critical I believe.

[MP]

About pragma ...



Cheers.

[JohnK]

*hum* Interesting topic.

Why don't you create the lisp on the fly and set it equal to a var then you could just eval the var and or destroy it.

I wrote a routine for my previous company that would allow me to control the users enviroment based on their department (It would read a list of names every time autocad started up...). But the first time the program was run it rewrote itself and did some other fancy stuff. But i used on the fly lisps in quite a bit of that program. It was quite slick. The only way i could ensure that i got a consistent result was to build a master program that once deployed it would re-write itself based on that users group (So an Electrical guy would have a diff program then a Mech an so on.)