[求助]：如何替换表中的某一项??

zhanyu80

如 想替换("f1" "f2" "f1") 中的某一项,如"f1"
但是
(subst "2" "f1" '("f1" "f2" "f1"))
结果是
("2" "f2" "2")

我只想换某一项,不想全换

没找到适合的命令

Underway

; index  = nth like
; newitm = new item to subst or nil to remove
; lst    = original list
; r_lst  = original list reversed
;
; Example: (setq rlist (reverse alist))
; (ALE_SUBST_NTH 2 nil alist rlist)


(defun ALE_SUBST_NTH (index newitem lst r_lst / len olditem)
  (if (> (setq len (- (length lst) (1+ index))) -1)
    (progn
      (setq olditem (nth index lst))
      (while (/= index (length (setq r_lst (cdr (member olditem r_lst))))))
      (while (/= len (length (setq lst (cdr (member olditem lst))))))
      (append (reverse r_lst) (if newitem (list newitem) nil) lst)
    )
    lst
  )
)

;;;  by Marc'Antonio Alessi

(setq sitelist '(("4" "Point of Interest") ("3" "Ramada1") ("3" "Ramada2")))


(ALE_SUBST_NTH 1 nil sitelist (reverse sitelist))

satan421

Marc'Antonio Alessi 的思路很好，学习了