[编程交流] Lisp新手：格式错误的参数

(defun testline ()
   ;define the function
   (setq a (getpoint "\nEnter First Point : "))
   ;get the first point     (setq b (getpoint "\nEnter Second Point : "))    ;get the second point
   (command "Line" a b "")
   ;draw the line
)    ;end defun

(defun c:testline (/ a b)
                                       ;define the function
 (if (and (setq a (getpoint "\nEnter First Point : "))
                                       ;get the first point
          (setq b (getpoint "\nEnter Second Point : "))
                                       ;get the second point
     )
   (command "_.Line" "_none" a "_none" b "")
                                       ;draw the line
 )                                     ;end defun
)

(defun[color="red"] C:[/color]testline (/ a b) [color="#2e8b57"];; add C: to execute the command testline [/color]
[color="#2e8b57"];; (/ a b) localize your variables[/color]
;define the function
(setq a (getpoint "\nEnter First Point : "))
;get the first point [color="#2e8b57"]; everything after the semi colon will be treated as a comment and will not be evaluated[/color]
[color="#2e8b57"];; move (setq b on the next line[/color]
(setq b (getpoint "\nEnter Second Point : "))        ;get the second point
(command "_.Line" "_none" a "_none" b "") 
[color="#2e8b57"];; underscore means to use the english equivalent of the command
;; use . or period just in case the command in use has been undefined
;; _none is a transparent command setting the snapmode to 0. If you didn't use _none or _non. If variable point a or b is close to an object either or both will snap to that object. 
[/color]
;draw the line
[color="red"](princ)[/color] [color="#2e8b57"];; exit quietly [/color]
)        ;end defun