feat(emacs): customisable syd-insert-file-name

modules/home/users/msyds/emacs/lisp/syd/prelude.el

@@ -199,15 +199,29 @@ form."
    (propertize " " 'display `(space :align-to (- right ,(+ 1 (length x)))))
    x))
 
+(defun syd-project-relative-file-name (file-name)
+  (file-relative-name file-name (project-root (project-current))))
+
+(defvar syd-insert-file-name-alist
+  `((,#'syd-project-relative-file-name . "Project-relative")
+    (,#'file-relative-name . "File-relative")
+    (,#'identity . "Absolute"))
+  "List of pairs where each cons is a function mapping paths to paths
+  or nil, and each cons is a string description.")
+
+(defun syd--evaluate-syd-insert-file-name-alist (path)
+  (cl-loop for (fn . lbl) in syd-insert-file-name-alist
+           for r = (funcall fn path)
+           when r
+           collect (cons r lbl)))
+
 (defun syd-insert-file-name ()
   (interactive)
-  (let* ((path (read-file-name "Path: " nil nil 'confirm))
-         (proj-root (project-root (project-current)))
-         (alts
-          `((,(file-relative-name path proj-root) . "Project-relative")
-            (,(file-relative-name path default-directory) . "File-relative")
-            (,path . "Absolute")
-            ("... (choose a dir)")))
+  (let* ((path (expand-file-name
+                (read-file-name "Path: " nil nil 'confirm)))
+         (choose-a-dir "... (choose a dir)")
+         (alts (cons `(,choose-a-dir)
+                     (syd--evaluate-syd-insert-file-name-alist path)))
          (choice
           (completing-read
            "Variant: "
@@ -221,7 +235,7 @@ form."
                           (syd--insert-file-name-annotation
                            desc))))))
                (_ (all-completions s (mapcar #'car alts) p)))))))
-    (if (equal choice "... (choose a root)")
+    (if (equal choice choose-a-dir)
         (insert (file-relative-name
                  path (read-file-name "Relative to: " nil nil
                                       'confirm)))