Updating `dired-directory` after renaming a file

Question

Q:   I have a list of strings: '("apple" "pear" "peach" "nectarine" "watermelon"). How can I replace "peach" with "plum" and maintain the same order of fruits?  [CAVEAT: The list may be very long and the nth position of the element to be replaced will not be known at the outset.]

BACKBROUND:

I am working on implementing wdired compatibility with a dired-mode listing of files created by calling:

(dired (directory-files-recursively "/path/to/directory" "" 'include-directories))

This creates a listing of absolute paths to files and directories. After modifying the wdired buffer, and pressing the command to finalize/commit the edits, here is what happens:

1.  The files get renamed correctly using a revised version of wdired-get-filename, thanks to the assistance of @Drew in a related thread: Dired / Wdired: How to test whether a filename is relative / absolute . [The renaming of directories (if applicable) will be dealt with by me on another day.]

2.  dired-readin-insert does not work correctly to populate the buffer anew because the variable dired-directory was not updated with the new absolute path of the files that got renamed.

   /path/to/bin/gls: cannot access '/path/to/filename': No such file or directory

There will undoubtedly be additional hurdles to implement this new wdired feature, so I understand this will be one baby step at a time. To resolve this particular question, I am looking for something a little fancier than delete and push/add-to-list. Specifically, I would like to programmatically replace the old filename with the new filename and maintain the same list order.

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EDIT:  Here is a link to the bug-report seeking an enhancement of wdired and dired: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=31601

Answer 1

(setq mylist '("apple" "pear" "peach" "nectarine" "watermelon"))

(defun ar-replace--in-list (elem replacement list)
  "Expects a LIST of strings.
ELEM: element to replace by arg REPLACEMENT"
  (let (newlist)
    (dolist (ele list)
      (push (if (string= ele elem) replacement ele) newlist))
    (nreverse newlist)))

So let's replace pear by cherry:

(ar-replace--in-list "pear" "cherry" mylist)

==>

("apple" "cherry" "peach" "nectarine" "watermelon")

Lists may contain other kind of elements than strings:

(defun ar-replace--in-list (pred elem replacement list)
  "Expects a LIST whose type must fit to arg PRED.
PRED: a function to select ELEM
ELEM: element to replace by arg REPLACEMENT"
  (let (newlist)
    (dolist (ele list)
      (push (if (funcall pred ele elem) replacement ele) newlist))
    (nreverse newlist)))

Call for this example:

(ar-replace--in-list 'string= "pear" "cherry" mylist)