APPEND Issue

[Bill Tillman]

I'm trying to use a simple code to build a list as I go through a REPEAT function. The variable for the list is nil when the REPEAT starts and that's where my problem seems to be.

...

(setq aa '(
         ("Extrusions" 3)
         ("Hardware" 6)
         ("Steel" 1)
         ("Viewports" 252)
         )
    )

  (setq al (length aa)) 
  (repeat al
    (append a '(car (car aa)))

When the APPEND line runs it crashes ???

[marko_ribar]

You are not doing anything with append line...

You should try with :

(repeat al

  (setq a (append a (list (car (car aa)))))

  (setq aa (cdr aa))

)

Or alternatively if you want to preserve aa :

(setq k -1)

(repeat al

  (setq a (append a (list (car (nth (setq k (1+ k)) aa)))))

)

 

Either way you should (setq a ... ) in order to get something after evaluation...

 

M.R.

[Bill Tillman]

Thanks. That (setq took care of it nicely.

[Tharwat]

Or this if you are searching for the return regardless of the use of any other function.

(mapcar 'car aa)