From 2c93878756d6e0c83853195a192ef6b80894c59f Mon Sep 17 00:00:00 2001
From: Case Duckworth <acdw@acdw.net>
Date: Thu, 30 Sep 2021 23:17:41 -0500
Subject: [PATCH] Re-write acdw-reading.el

---
 lisp/acdw-reading.el | 105 ++++++++++++++++++++++++++++---------------
 1 file changed, 69 insertions(+), 36 deletions(-)

diff --git a/lisp/acdw-reading.el b/lisp/acdw-reading.el
index e3d5716..ff4f0c2 100644
--- a/lisp/acdw-reading.el
+++ b/lisp/acdw-reading.el
@@ -17,8 +17,60 @@
 
 ;;; Code:
 
-(defvar-local //indicate-empty-lines nil)
-(defvar-local //indicate-buffer-boundaries nil)
+;;; Customizations
+
+(defgroup reading nil
+  "Group for Reading mode customizations."
+  :prefix "reading-"
+  :group 'convenience)                  ; i need to figure this out
+
+(defcustom reading-vars '((indicate-empty-lines . nil)
+                          (indicate-buffer-boundaries . nil))
+  "Alist of variables to set in function `reading-mode'.
+The car of each cell is the variable name, and the cdr is the
+value to set it to."
+  :type '(alist :key-type variable
+                :value-type sexp))
+
+(defcustom reading-modes '((display-fill-column-indicator-mode . -1)
+                           (blink-cursor-mode . -1))
+  "Alist of modes to set in function `reading-mode'.
+The car of each cell is the function name, and the cdr is the
+value to call it with."
+  :type '(alist :key-type function
+                :value-type sexp))
+
+;;; Internal
+
+(defvar reading--remembered-template "reading--remembered-%s-value"
+  "The template passed to `format' for remembered modes and variables.")
+
+(defun reading--remember (things func)
+  "Apply FUNC to THINGS, remembering their previous value for later."
+  (declare (indent 1))
+  (unless (listp things)
+    (setq things (list things)))
+  (dolist (thing things)
+    (set (make-local-variable
+          (intern (format reading--remembered-template thing)))
+         (and (boundp thing)
+              (symbol-value thing)))
+    (funcall func thing)))
+
+(defun reading--recall (things func)
+  "Recall previously remembered THINGS by applying FUNC to them.
+FUNC should be a function with the signature (THING REMEMBERED-SETTING)."
+  (declare (indent 1))
+  (unless (listp things)
+    (setq things (list things)))
+  (dolist (thing things)
+    (with-demoted-errors "reading--recall: %S"
+      (let ((value (symbol-value
+                    (intern
+                     (format reading--remembered-template thing)))))
+        (funcall func thing value)))))
+
+;;; Mode
 
 ;;;###autoload
 (define-minor-mode reading-mode
@@ -27,41 +79,22 @@
   :lighter " Read"
   :keymap (make-sparse-keymap)
   (if reading-mode
-      (progn ;; turn on
-        ;; settings
-        (setq-local //indicate-empty-lines indicate-empty-lines
-                    indicate-empty-lines nil
-                    //indicate-buffer-boundaries indicate-buffer-boundaries
-                    indicate-buffer-boundaries nil)
-        ;; disable modes
-        (dolist (mode '(display-fill-column-indicator-mode
-                        blink-cursor-mode))
-          (when (fboundp mode)
-            (set (make-local-variable
-                  (intern (format "//%s" mode)))
-                 (and (boundp mode)
-                      (symbol-value mode)))
-            (funcall mode -1)))
-        ;; enable modes
-        (dolist (mode '(olivetti-mode))
-          (when (fboundp mode)
-            (set (make-local-variable
-                  (intern (format "//%s" mode)))
-                 (and (boundp mode)
-                      (symbol-value mode)))
-            (funcall mode +1))))
+      ;; turn on
+      (progn
+        (reading--remember (mapcar #'car reading-vars)
+          (lambda (var)
+            (set (make-local-variable var)
+                 (cdr (assoc var reading-vars)))))
+        (reading--remember (mapcar #'car reading-modes)
+          (lambda (mode)
+            (funcall mode (cdr (assoc mode reading-modes))))))
     ;; turn off
-    ;; restore settings
-    (setq-local indicate-empty-lines //indicate-empty-lines
-                indicate-buffer-boundaries //indicate-buffer-boundaries)
-    ;; restore modes
-    (dolist (mode '(display-fill-column-indicator-mode
-                    olivetti-mode
-                    blink-cursor-mode))
-      (when (fboundp mode)
-        (funcall mode (if (symbol-value (intern (format "//%s" mode)))
-                          +1
-                        -1))))))
+    (reading--recall (mapcar #'car reading-vars)
+      (lambda (var orig-val)
+        (set (make-local-variable var) orig-val)))
+    (reading--recall (mapcar #'car reading-modes)
+      (lambda (mode orig-setting)
+        (funcall mode (if orig-setting +1 -1))))))
 
 (provide 'acdw-reading)
 ;;; acdw-reading.el ends here