Prefer struct/set! to setf

I originally tried using `struct/set` instead of `setf`, which I had forgotten
was the *immutable* version of `struct/set!`. When this didn't work, I reverted
to `setf`. After a good night's sleep and with a fresh set of eyes, I dug into
the issue and discovered that `struct/set!` was what I wanted the whole.

I am curious now about `struct/update` versus `struct/update!`; shouldn't the
former be immutable and the latter be mutable? I'll save that investigation for
a later date.

1 files changed, 9 insertions, 4 deletions

diff --git a/configs/shared/.emacs.d/wpc/buffer.el b/configs/shared/.emacs.d/wpc/buffer.el
index ea2c5945a1..bd10192301 100644
--- a/configs/shared/.emacs.d/wpc/buffer.el
+++ b/configs/shared/.emacs.d/wpc/buffer.el
@@ -27,6 +27,7 @@
 (require 'maybe)
 (require 'set)
 (require 'cycle)
+(require 'struct)
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Library
@@ -112,14 +113,18 @@ Return a reference to that buffer."
     (if (> (ts-diff (ts-now) last-called)
            buffer/source-code-timeout)
         (progn
-          (setf (source-code-cycle-cycle buffer/source-code-cycle-state)
-                (cycle/from-list (buffer/source-code-buffers)))
+          (struct/set! source-code-cycle
+                       cycle
+                       (cycle/from-list (buffer/source-code-buffers))
+                       buffer/source-code-cycle-state)
           (let ((cycle (source-code-cycle-cycle
                         buffer/source-code-cycle-state)))
             (funcall cycle-fn cycle)
             (switch-to-buffer (cycle/current cycle)))
-          (setf (source-code-cycle-last-called buffer/source-code-cycle-state)
-                (ts-now)))
+          (struct/set! source-code-cycle
+                       last-called
+                       (ts-now)
+                       buffer/source-code-cycle-state))
       (progn
         (funcall cycle-fn cycle)
         (switch-to-buffer (cycle/current cycle))))))