如何定製 mode-line-buffer-identification 顯示更多path components

Emacs-general
1

~/Dev/llvm-project/llvm/include/llvm/Support/Endian.h buffer-name 是 Endian.h，希望能傳遞一個函數自定義，多帶幾個path components，顯示爲 Support/Endian.h

2
3

我用 spacemacs 的。还要折腾下 spaceline 怎么改 buffer-id

先写成这样了

  (spaceline-define-segment my-buffer-id
    "Comment meow"
    (let ((name buffer-file-name)
          (f (lambda (s) (propertize s 'face 'mode-line-buffer-id))))
      (if (and name (string-match-p "/llvm/" name))
          (cond
           ((string-match "/include/clang-c/\\(.*\\)" name)
            (concat "clang-c/" (funcall f (match-string 1 name))))
           ((and (string-match "/\\([a-z]*\\)/include/\\([a-z]*\\)/\\(.*\\)" name)
                 (string= (match-string 1 name) (match-string 2 name)))
            (concat (substring (match-string 1 name) 0 1) "/" (funcall f (match-string 3 name))))
           ((string-match "/\\([a-z]*\\)/lib/\\(.*\\)" name)
            (concat (substring (match-string 1 name) 0 1) "/" (funcall f (match-string 2 name))))
           (t (funcall f (buffer-name))))
        (funcall f (buffer-name)))))

  ;; Default additional-segments causes trouble.
  ;; Without this, the active window does not show buffer-id, weird.
  ;; (spaceline-spacemacs-theme nil)
  (apply 'spaceline--theme
         '((persp-name
            workspace-number
            window-number)
           :fallback evil-state
           :face highlight-face
           :priority 0)
         '((buffer-modified buffer-size my-buffer-id remote-host)
           :priority 5))