Help with bad argument type: lentityp nil

[mattsibum]

Hi, got this part of a lisp that is returning an error when nothing is selected

"bad argument type: lentityp nil"

Not sure why the 'if' statement isn't working, displaying the "Nothing Selected... Program Closing" message when 'objsel' variable returns nil.

(if 
(setq objsel (entget (car (nentsel "\nSelect Objects to Change Layer Colour..."))))
(progn
(setq layget (cdr (assoc 8 objsel)))
(progn
(if 
(and (/= layget "0")(/= layget "Defpoints"))
(command "-layer" "c" laycol layget "" "")
(princ "\nCannot Modify Layer 0 or Defpoints...")
);END IF
);END PROGN
);END PROGN
(princ "\nNothing Selected... Program Closing...")
);END IF

Any help would be great.
Matt

[Walt Bedinger]

(if (setq obj (nentsel "\nSelect Objects to Change Layer Colour..."))
(progn
(setq objsel (entget (car obj))
layget (cdr (assoc 8 objsel))
)
(progn
(if (and (/= layget "0")(/= layget "Defpoints"))
(command "-layer" "c" laycol layget "" "")
(prompt "\nCannot Modify Layer 0 or Defpoints...")
);END IF
);END PROGN
);END PROGN
(prompt "\nNothing Selected... Program Closing...")
);END IF

[mattsibum]

Beautiful :-)

Thanks a lot.. Seems i am trying to achieve too much with one line of code.

[Cap'n Mac]

The trick is to remember to always check for a nil condition from any user response.

That, or to "force" one using (initget).

The other thing to watch for is the last value of a (while) or (tblnext) or similar loop.

One of the great freedoms LISP gives is that you need not define a variable, it can be integer, real, string, atom, list, whatever, and it can change each time it is (set(equal))--aka (setq)--to something. Which is why the (typ) subr is needful, and, occasionally, handy.