moved non-config functions into a new lisp directory

We will now put non-config related functions (any elisp libraries or
snippets that I write) into a new ".emacs.d/lisp" directory and separate them from
the config code in the ".emacs.d/config" directory.

During the transition I decided to move and rewrite the logic that
adds all of the libraries to load-path. Now this logic is in two top
level files (load-config.el load-local-lisp.el). I needed to remove
the config-programming-languages module because it conflicted with the
new load-path logic (it was mostly useless anyways).

The man advice functions are deleted in this commit but they will be
added into the new ".emacs.d/lisp" directory soon.

1 files changed, 54 insertions, 0 deletions

diff --git a/lisp/backup-before-save/backup-before-save.el b/lisp/backup-before-save/backup-before-save.el
new file mode 100644
index 0000000..5277fff
--- /dev/null
+++ b/lisp/backup-before-save/backup-before-save.el
@@ -0,0 +1,54 @@
+(defvar backup-before-save-directory (file-name-concat user-emacs-directory "backups"))
+
+(unless (file-exists-p backup-before-save-directory)
+  (mkdir backup-before-save-directory))
+
+(defun backup-before-save-format-path (path number)
+  (format "%s.~%s~" path number))
+
+(defun backup-before-save-extension (path)
+  (let* ((i (string-search "." (reverse path)))
+         (extension (substring path (- (length path) i))))
+    extension))
+
+(defun backup-before-save-no-extension (path)
+  (let* ((i (string-search "." (reverse path)))
+         (no-extension (substring path 0 (- (length path) (+ i 1)))))
+    no-extension))
+
+(defun backup-before-save-number (path)
+  (let* ((extension (backup-before-save-extension path))
+         (extracted (substring extension 1 (- (length extension) 1)))
+         (as-number (unless (zerop (length extracted))
+                      (string-to-number extracted))))
+    as-number))
+
+(defun backup-before-save-shift-path (path)
+  (let* ((without-extension (backup-before-save-no-extension path))
+         (number (backup-before-save-number path))
+         (next-number (+ number 1))
+         (shifted-path (backup-before-save-format-path
+                        without-extension
+                        next-number)))
+    shifted-path))
+
+(defun backup-before-save-shift-backup (path)
+  (let ((next-path (backup-before-save-shift-path path)))
+    (when (file-exists-p next-path)
+        (backup-before-save-shift-backup next-path))
+    (rename-file path next-path)))
+
+(defun backup-before-save-function ()
+  (unless backup-inhibited
+    (let* ((full-path (buffer-file-name))
+           (base-path (file-name-nondirectory full-path))
+           (backup-full-path (file-name-concat backup-before-save-directory base-path))
+           (backup-full-path-numbered (backup-before-save-format-path backup-full-path 0)))
+      (when (file-exists-p full-path)
+        (when (file-exists-p backup-full-path-numbered)
+          (backup-before-save-shift-backup backup-full-path-numbered))
+        (copy-file full-path backup-full-path-numbered)))))
+
+(add-hook 'before-save-hook 'backup-before-save-function)
+
+(provide 'backup-before-save)