Prefer '(evenp A)' to '(= 0 (% A 2))'

* lisp/calc/calc-comb.el (math-prime-test):
* lisp/calc/calc-keypd.el (calc-keypad-press):
* lisp/calc/calc-math.el (math-sqrt):
(math-sqrt-raw):
* lisp/calc/calc-misc.el (math-iipow):
(math-iipow-show):
* lisp/calc/calc-stat.el (calcFunc-vmedian):
* lisp/calendar/cal-tex.el (cal-tex-cursor-filofax-2week):
(cal-tex-cursor-filofax-daily):
* lisp/elec-pair.el (electric-pair-post-self-insert-function):
* lisp/emacs-lisp/checkdoc.el (checkdoc-in-example-string-p):
* lisp/emacs-lisp/eieio.el (defclass):
* lisp/emacs-lisp/ert-x.el (ert-propertized-string):
* lisp/emacs-lisp/ert.el (ert--significant-plist-keys):
(ert--plist-difference-explanation):
* lisp/emacs-lisp/helper.el (Helper-help-scroller):
* lisp/emacs-lisp/pcase.el (pcase-setq):
* lisp/files-x.el (setq-connection-local):
* lisp/gnus/gnus-uu.el (gnus-uu-post-encoded):
* lisp/gnus/message.el (message-make-in-reply-to):
* lisp/gnus/nndiary.el (nndiary-last-occurrence):
(nndiary-next-occurrence):
* lisp/mail/rfc2047.el (rfc2047-decode-region):
* lisp/play/5x5.el (5x5-draw-grid):
* lisp/play/gametree.el (gametree-compute-reduced-score):
(gametree-insert-new-leaf):
(gametree-break-line-here):
* lisp/play/zone.el (zone-fret):
* lisp/vc/ediff-ptch.el (ediff-get-patch-buffer):
* lisp/yank-media.el (yank-media--utf-16-p): Prefer '(evenp A)' to
'(= 0 (% A 2))' and variations thereof.

6 files changed, 8 insertions, 8 deletions

diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index dd3da9ae8c0..3541e3d0a57 100644
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -2109,7 +2109,7 @@ The text checked is between START and LIMIT."
 	(goto-char start)
 	(while (and (< (point) p) (re-search-forward "\\\\\"" limit t))
 	  (setq c (1+ c)))
-	(and (< 0 c) (= (% c 2) 0))))))
+	(and (< 0 c) (evenp c))))))
 
 (defun checkdoc-in-abbreviation-p (begin)
   "Return non-nil if point is at an abbreviation.
diff --git a/lisp/emacs-lisp/eieio.el b/lisp/emacs-lisp/eieio.el
index 8665934ebfd..0f029813f80 100644
--- a/lisp/emacs-lisp/eieio.el
+++ b/lisp/emacs-lisp/eieio.el
@@ -115,7 +115,7 @@ and reference them using the function `class-option'."
   (cl-check-type superclasses list)
 
   (cond ((and (stringp (car options-and-doc))
-              (/= 1 (% (length options-and-doc) 2)))
+              (evenp (length options-and-doc)))
          (error "Too many arguments to `defclass'"))
         ((and (symbolp (car options-and-doc))
               (oddp (length options-and-doc)))
diff --git a/lisp/emacs-lisp/ert-x.el b/lisp/emacs-lisp/ert-x.el
index 147787d3d38..0dacec130a0 100644
--- a/lisp/emacs-lisp/ert-x.el
+++ b/lisp/emacs-lisp/ert-x.el
@@ -260,7 +260,7 @@ structure with the plists in ARGS."
                (string (let ((begin (point)))
                          (insert x)
                          (set-text-properties begin (point) current-plist)))
-               (list (unless (zerop (mod (length x) 2))
+               (list (unless (evenp (length x))
                        (error "Odd number of args in plist: %S" x))
                      (setq current-plist x))))
     (buffer-string)))
diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 5d1b9f2acbb..e8012326eb3 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -576,7 +576,7 @@ Return nil if they are."
 
 (defun ert--significant-plist-keys (plist)
   "Return the keys of PLIST that have non-null values, in order."
-  (cl-assert (zerop (mod (length plist) 2)) t)
+  (cl-assert (evenp (length plist)) t)
   (cl-loop for (key value . rest) on plist by #'cddr
            unless (or (null value) (memq key accu)) collect key into accu
            finally (cl-return accu)))
@@ -587,8 +587,8 @@ Return nil if they are."
 Returns nil if they are equivalent, i.e., have the same value for
 each key, where absent values are treated as nil.  The order of
 key/value pairs in each list does not matter."
-  (cl-assert (zerop (mod (length a) 2)) t)
-  (cl-assert (zerop (mod (length b) 2)) t)
+  (cl-assert (evenp (length a)) t)
+  (cl-assert (evenp (length b)) t)
   ;; Normalizing the plists would be another way to do this but it
   ;; requires a total ordering on all lisp objects (since any object
   ;; is valid as a text property key).  Perhaps defining such an
diff --git a/lisp/emacs-lisp/helper.el b/lisp/emacs-lisp/helper.el
index d8f758d2fe5..8a173219545 100644
--- a/lisp/emacs-lisp/helper.el
+++ b/lisp/emacs-lisp/helper.el
@@ -80,7 +80,7 @@
 		 (recenter))
                 ((and (or (eq continue 'backspace)
                           (eq continue ?\177))
-                      (zerop (% state 2)))
+                      (evenp state))
 		 (scroll-down))
 		(t (setq continue nil))))))))
 
diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el
index a6a4751f49a..c68b8961ee3 100644
--- a/lisp/emacs-lisp/pcase.el
+++ b/lisp/emacs-lisp/pcase.el
@@ -370,7 +370,7 @@ undetected, binding variables to arbitrary values, such as nil.
   (cond
    (args
     (let ((arg-length (length args)))
-      (unless (= 0 (mod arg-length 2))
+      (unless (evenp arg-length)
         (signal 'wrong-number-of-arguments
                 (list 'pcase-setq (+ 2 arg-length)))))
     (let ((result))