*.el: Minor improvements and simplifications

* emms-playlist-limit.el (emms-playlist-limit--limit-playlist): Simplify.

* emms-playing-time.el (emms-playing-time-display): Simplify.

* emms-player-mpv.el (emms-player-mpv-ipc-proc)
(emms-player-mpv-ipc-connect-command, emms-player-mpv-ipc-id)
(emms-player-mpv-ipc-stop-command)
(emms-player-mpv-event-connect-hook)
(emms-player-mpv-ipc-conn-emacs-26.1-workaround): Fit docstrings with
80 columns.

* emms-player-mpd.el (emms-player-mpd-ensure-process): Simplify `if`
with identical branches.

* emms-browser.el (emms-browser-run-mode-hooks): Simplify and move it
out of `eval-and-compile`.
(emms-browser-sort-cadr, emms-browser-sort-car): Add `debug` spec.

patch by Stefan Monnier

7 files changed, 155 insertions, 146 deletions

diff --git a/emms-browser.el b/emms-browser.el
index fcb4ef3..2adada7 100644
--- a/emms-browser.el
+++ b/emms-browser.el
@@ -482,19 +482,20 @@ Called once for each directory."
 ;; --------------------------------------------------
 
 (eval-and-compile
-  (if (fboundp 'with-selected-window)
-      (defalias 'emms-browser-with-selected-window 'with-selected-window)
+  (if (fboundp 'with-selected-window)   ;Emacs-22
+      (defalias 'emms-browser-with-selected-window #'with-selected-window)
     (defmacro emms-browser-with-selected-window (window &rest body)
       (ignore window)
       ;; this emulates the behavior introduced earlier, though it
       ;; might be best to do something with `window'
       `(save-selected-window ,body)))
   (put 'emms-browser-with-selected-window 'lisp-indent-function 1)
-  (put 'emms-browser-with-selected-window 'edebug-form-spec '(form body))
+  (put 'emms-browser-with-selected-window 'edebug-form-spec '(form body)))
 
-  (if (fboundp 'run-mode-hooks)
-      (defalias 'emms-browser-run-mode-hooks 'run-mode-hooks)
-    (defalias 'emms-browser-run-mode-hooks 'run-hooks)))
+(defalias 'emms-browser-run-mode-hooks
+  (if (fboundp 'run-mode-hooks)         ;Emacs-22
+      #'run-mode-hooks
+    #'run-hooks))
 
 ;; --------------------------------------------------
 ;; General mode setup
@@ -534,7 +535,7 @@ example function is `emms-browse-by-artist'."
 (defun emms-browser-mode (&optional no-update)
   "A major mode for the Emms browser.
 \\{emms-browser-mode-map}"
-      ;; create a new buffer
+  ;; create a new buffer
   (interactive)
 
   (use-local-map emms-browser-mode-map)
@@ -592,10 +593,10 @@ If a browser search exists, return it."
   "Create an interactive function emms-browse-by-NAME."
   (let ((funname (intern (concat "emms-browse-by-" name)))
         (funcdesc (concat "Browse by " name ".")))
-  `(defun ,funname ()
-     ,funcdesc
-     (interactive)
-     (emms-browse-by ,type))))
+    `(defun ,funname ()
+       ,funcdesc
+       (interactive)
+       (emms-browse-by ,type))))
 
 (defun emms-browse-by (type)
   "Render a top level buffer based on TYPE."
@@ -699,7 +700,7 @@ For 'info-year TYPE, use 'info-originalyear, 'info-originaldate and
            (sort-subr nil
                       #'forward-line #'end-of-line
                       (lambda () (buffer-substring-no-properties
-                             (line-beginning-position) (line-end-position)))
+				  (line-beginning-position) (line-end-position)))
                       nil
                       emms-browser-alpha-sort-function))
        (sort-lines nil (point-min) (point-max))))))
@@ -796,14 +797,14 @@ artist1 -> album1 -> *track* 1.."
   (let ((key (car entry))
         (track (cadr entry))
         artist title) ;; only the first track
-  (cond
-   ((eq type 'info-title)
-    (setq artist (emms-track-get track 'info-artist))
-    (setq title (emms-track-get track 'info-title))
-    (if (not (and artist title))
-        key
-      (concat artist " - " title)))
-   (t key))))
+    (cond
+     ((eq type 'info-title)
+      (setq artist (emms-track-get track 'info-artist))
+      (setq title (emms-track-get track 'info-title))
+      (if (not (and artist title))
+          key
+	(concat artist " - " title)))
+     (t key))))
 
 (defun emms-browser-track-number (track)
   "Return a string representation of a track number.
@@ -863,7 +864,7 @@ Items with no metadata for TYPE will be placed in 'misc'"
     (dolist (track tracks)
       (setq key (emms-browser-get-track-field track type))
       (when (eq type 'info-title)
-          ;; try and make every track unique
+        ;; try and make every track unique
         (setq tracknum (emms-browser-track-number track))
         (if (string= tracknum "")
             (setq key (file-name-nondirectory
@@ -915,6 +916,7 @@ TYPE is the metadata to make the alist by - eg. if it's
 This sorting predicate will compare the cadr of each entry.
 SORT-FUNC should be a playlist sorting predicate like
 `emms-playlist-sort-by-natural-order'."
+  (declare (debug t))
   `(lambda (a b)
      (funcall ,sort-func (cadr a) (cadr b))))
 
@@ -923,6 +925,7 @@ SORT-FUNC should be a playlist sorting predicate like
 This sorting predicate will compare the car of each entry.
 SORT-FUNC should be a playlist sorting predicate like
 `emms-playlist-sort-by-natural-order'."
+  (declare (debug t))
   `(lambda (a b)
      (funcall ,sort-func (car a) (car b))))
 
@@ -931,7 +934,7 @@ SORT-FUNC should be a playlist sorting predicate like
 Uses `emms-browser-track-sort-function'."
   (if emms-browser-track-sort-function
       (sort alist (emms-browser-sort-cadr
-                  emms-browser-track-sort-function))
+                   emms-browser-track-sort-function))
     alist))
 
 (defun emms-browser-sort-by-name (alist)
@@ -939,7 +942,7 @@ Uses `emms-browser-track-sort-function'."
 Uses `emms-browser-alpha-sort-function'."
   (if emms-browser-alpha-sort-function
       (sort alist (emms-browser-sort-car
-                  emms-browser-alpha-sort-function))
+                   emms-browser-alpha-sort-function))
     alist))
 
 (defun emms-browser-sort-by-year-or-name (alist)
@@ -1405,12 +1408,12 @@ tracks from point, it does not delete files."
     (when (numberp delete) (setq delete nil))
     (when delete
       (save-mark-and-excursion
-       (when (use-region-p) (goto-char start))
-       (let ((lines (min count (- (line-number-at-pos (point-max)) (line-number-at-pos (point))))))
-         (dotimes (_ lines)
-           ;; TODO: Test this!
-           (setq tracks (append tracks (emms-browser-tracks-at-point)))
-           (forward-line))))
+	(when (use-region-p) (goto-char start))
+	(let ((lines (min count (- (line-number-at-pos (point-max)) (line-number-at-pos (point))))))
+          (dotimes (_ lines)
+            ;; TODO: Test this!
+            (setq tracks (append tracks (emms-browser-tracks-at-point)))
+            (forward-line))))
       (unless (yes-or-no-p
                (format "Really permanently delete these %d tracks? " (length tracks)))
         (error "Cancelled!"))
@@ -1497,47 +1500,47 @@ configuration."
             #'emms-browser-hide-linked-window)
   ;; switch to the playlist window when adding tracks?
   (add-hook 'emms-browser-tracks-added-hook
-               (lambda (start-of-tracks) (interactive)
-                 (let (playlist-window)
-                   (when emms-browser-switch-to-playlist-on-add
-                     (emms-smart-browse))
-                   ;; center on the first added track/group name
-                   (when
-                       (setq playlist-window
-                             (emms-browser-get-linked-window))
-                     (emms-browser-with-selected-window
-                         playlist-window
-                       (goto-char start-of-tracks)
-                       (recenter '(4)))))))
+            (lambda (start-of-tracks) (interactive)
+              (let (playlist-window)
+                (when emms-browser-switch-to-playlist-on-add
+                  (emms-smart-browse))
+                ;; center on the first added track/group name
+                (when
+                    (setq playlist-window
+                          (emms-browser-get-linked-window))
+                  (emms-browser-with-selected-window
+                      playlist-window
+                    (goto-char start-of-tracks)
+                    (recenter '(4)))))))
   (let (wind)
-  (cond
-   ((eq major-mode 'emms-browser-mode)
-    (setq wind (emms-browser-get-linked-window))
-    ;; if the playlist window is visible, select it
-    (if wind
-        (select-window wind)
-      ;; otherwise display and select it
-      (select-window (emms-browser-display-playlist))))
-   ((eq major-mode 'emms-playlist-mode)
-    (setq wind (emms-browser-get-linked-window))
-    ;; if the playlist window is selected, and the browser is visible,
-    ;; hide both
-    (if wind
-        (progn
+    (cond
+     ((eq major-mode 'emms-browser-mode)
+      (setq wind (emms-browser-get-linked-window))
+      ;; if the playlist window is visible, select it
+      (if wind
           (select-window wind)
-          (emms-browser-bury-buffer)
-          ;; After a browser search, the following buffer could be the
-          ;; unfiltered browser, which we want to bury as well.  We don't want
-          ;; to call `emms-browser-hide-display-hook' for this one so we bury it
-          ;; directly.
-          (when (eq major-mode 'emms-browser-mode)
-            (bury-buffer)))
-      ;; otherwise bury both
-      (bury-buffer)
-      (emms-browser-hide-linked-window)))
-   (t
-    ;; show both
-    (emms-browser)))))
+	;; otherwise display and select it
+	(select-window (emms-browser-display-playlist))))
+     ((eq major-mode 'emms-playlist-mode)
+      (setq wind (emms-browser-get-linked-window))
+      ;; if the playlist window is selected, and the browser is visible,
+      ;; hide both
+      (if wind
+          (progn
+            (select-window wind)
+            (emms-browser-bury-buffer)
+            ;; After a browser search, the following buffer could be the
+            ;; unfiltered browser, which we want to bury as well.  We don't want
+            ;; to call `emms-browser-hide-display-hook' for this one so we bury it
+            ;; directly.
+            (when (eq major-mode 'emms-browser-mode)
+              (bury-buffer)))
+	;; otherwise bury both
+	(bury-buffer)
+	(emms-browser-hide-linked-window)))
+     (t
+      ;; show both
+      (emms-browser)))))
 
 (defun emms-browser-get-linked-buffer ()
   "Return linked buffer (eg browser if playlist is selected."
@@ -1867,11 +1870,11 @@ If > album level, most of the track data will not make sense."
          (name (cond
                 ((or (eq type 'info-year)
                      (eq type 'info-genre)) "year/genre")
-                 ((eq type 'info-artist) "artist")
-                 ((eq type 'info-composer) "composer")
-                 ((eq type 'info-performer) "performer")
-                 ((eq type 'info-album) "album")
-                 ((eq type 'info-title) "track"))))
+                ((eq type 'info-artist) "artist")
+                ((eq type 'info-composer) "composer")
+                ((eq type 'info-performer) "performer")
+                ((eq type 'info-album) "album")
+                ((eq type 'info-title) "track"))))
     (intern
      (concat "emms-browser-" name "-face"))))
 
@@ -2015,11 +2018,11 @@ the text that it generates."
 This:
  - defines an interactive function M-x emms-browser-show-NAME.
  - defines a variable emms-browser-filter-NAME of (name . func).
- - adds the filter to emms-browser-filters."
+ - adds the filter to `emms-browser-filters'."
   (let ((funcnam (intern (concat "emms-browser-show-" name)))
         (var  (intern (concat "emms-browser-filter-" name)))
         (desc (concat "Filter the cache using rule '"
-                       name "'")))
+                      name "'")))
     `(progn
        (defvar ,var nil ,desc)
        (setq ,var (cons ,name ,func))
@@ -2046,7 +2049,7 @@ This does not refresh the current buffer."
   "Redisplay with the next filter."
   (interactive)
   (let* ((list (if reverse
-                  (reverse emms-browser-filters)
+                   (reverse emms-browser-filters)
                  emms-browser-filters))
          (key emms-browser-current-filter-name)
          (next (cadr (member (assoc key list) list))))
diff --git a/emms-player-mpd.el b/emms-player-mpd.el
index 7ae48dc..39f23d5 100644
--- a/emms-player-mpd.el
+++ b/emms-player-mpd.el
@@ -311,9 +311,7 @@ return at the end of a request.")
                           #'emms-player-mpd-sentinel)
     (setq emms-player-mpd-queue
           (tq-create emms-player-mpd-process))
-    (if (fboundp 'set-process-query-on-exit-flag)
-        (set-process-query-on-exit-flag emms-player-mpd-process nil)
-      (set-process-query-on-exit-flag emms-player-mpd-process nil))
+    (set-process-query-on-exit-flag emms-player-mpd-process nil)
     ;; send password
     (when (stringp emms-player-mpd-server-password)
       (tq-enqueue emms-player-mpd-queue
diff --git a/emms-player-mpv.el b/emms-player-mpv.el
index 69f81fa..399ec82 100644
--- a/emms-player-mpv.el
+++ b/emms-player-mpv.el
@@ -181,7 +181,8 @@ if it refuses to exit cleanly on `emms-player-mpv-proc-stop'.")
 
 
 (defvar emms-player-mpv-ipc-proc nil
-  "Unix socket process that communicates with running `emms-player-mpv-proc' instance.")
+  "Process that communicates with running `emms-player-mpv-proc' instance.
+Connected via a Unix socket.")
 
 (defvar emms-player-mpv-ipc-buffer " *emms-player-mpv-ipc*"
   "Buffer to associate with `emms-player-mpv-ipc-proc' socket/pipe process.")
@@ -193,33 +194,40 @@ if it refuses to exit cleanly on `emms-player-mpv-proc-stop'.")
   "List of delays before initiating socket connection for new mpv process.")
 
 (defvar emms-player-mpv-ipc-connect-command nil
-  "JSON command for `emms-player-mpv-ipc-sentinel' to run as soon as it connects to mpv.
-I.e. last command that either initiated connection or was used while connecting to mpv.
+  "JSON command for `emms-player-mpv-ipc-sentinel' to run when it connects to mpv.
+I.e. last command that either initiated connection or was used while
+connecting to mpv.
 Set by `emms-player-mpv-start' and such,
 cleared once it gets sent by `emms-player-mpv-ipc-sentinel'.")
 
 (defvar emms-player-mpv-ipc-id 1
-  "Auto-incremented value sent in JSON requests for request_id and observe_property id's.
-Use `emms-player-mpv-ipc-id-get' to get and increment this value, instead of using it directly.
-Wraps-around upon reaching `emms-player-mpv-ipc-id-max' (unlikely to ever happen).")
+  "Auto-incremented counter for unique JSON request identifiers.
+Use for for `request_id' and `observe_property' identifiers.
+Use `emms-player-mpv-ipc-id-get' to get and increment this value,
+instead of using it directly.
+Wraps-around upon reaching `emms-player-mpv-ipc-id-max'
+\(unlikely to ever happen).")
 
 (defvar emms-player-mpv-ipc-id-max (expt 2 30)
   "Max value for `emms-player-mpv-ipc-id' to wrap around after.
-Should be fine with both mpv and emacs, and probably never reached anyway.")
+Should be fine with both mpv and Emacs, and probably never reached anyway.")
 
 (defvar emms-player-mpv-ipc-req-table nil
   "Auto-initialized hash table of outstanding API req_ids to their handler funcs.")
 
 (defvar emms-player-mpv-ipc-stop-command nil
   "Internal flag to track when stop command starts/finishes before next loadfile.
-Set to either nil, t or playback start function to call on end-file event after stop command.
-This is a workaround for mpv-0.30+ behavior, where 'stop + loadfile' only runs 'stop'.")
+Set to either nil, t or the playback start function to call on end-file event
+after stop command.
+This is a workaround for mpv-0.30+ behavior, where 'stop + loadfile' only
+runs 'stop'.")
 
 
 (defvar emms-player-mpv-event-connect-hook nil
-  "Normal hook run right after establishing new JSON IPC
-connection to mpv instance and before `emms-player-mpv-ipc-connect-command'	if any.
-Best place to send any observe_property, request_log_messages, enable_event commands.
+  "Normal hook run right after establishing new JSON IPC connection to mpv. 
+Run before `emms-player-mpv-ipc-connect-command', if any.
+Best place to send any `observe_property', `request_log_messages',
+`enable_event' commands.
 Use `emms-player-mpv-ipc-id-get' to get unique id values for these.
 See also `emms-player-mpv-event-functions'.")
 
@@ -246,8 +254,9 @@ to indicate that playback should stop instead of switching to next track.")
   (and (= emacs-major-version 26)
        (= emacs-minor-version 1))
   "Non-nil to enable workaround for issue #31901 in emacs 26.1.
-Emacs 26.1 fails to indicate missing socket file error for unix socket network processes
-that were started with :nowait t, so blocking connections are used there instead.")
+Emacs 26.1 fails to indicate missing socket file error for unix socket
+network processes that were started with :nowait t, so blocking connections
+are used there instead.")
 
 
 ;; ----- helpers
diff --git a/emms-playing-time.el b/emms-playing-time.el
index 11dc9e3..e99dc64 100644
--- a/emms-playing-time.el
+++ b/emms-playing-time.el
@@ -165,55 +165,51 @@ could call `emms-playing-time-enable-display' and
 (defun emms-playing-time-display ()
   "Display playing time on the mode line."
   (setq emms-playing-time (round (1+ emms-playing-time)))
-  (setq emms-playing-time-string "")
-  (when emms-playing-time-display-p
-    (let* ((min (/ emms-playing-time 60))
-           (sec (% emms-playing-time 60))
-           (total-playing-time
-            (or (emms-track-get
-                 (emms-playlist-current-selected-track)
-                 'info-playing-time)
-                0))
-           (total-min-only (/ total-playing-time 60))
-           (total-sec-only (% total-playing-time 60)))
-      (cl-case emms-playing-time-style
-	((downtime)			; `downtime' style
-	 (setq emms-playing-time-string
-               (emms-replace-regexp-in-string
-                " " "0"
-                (if (or emms-playing-time-display-short-p
-                        ;; unable to get total playing-time
-                        (eq total-playing-time 0))
-                    (format "%2d:%2d" min sec)
-                  (format "-%2d:%2d"
-			  (/ (- total-playing-time emms-playing-time) 60)
-			  (% (- total-playing-time sec) 60))))))
-        ((bar)                          ; `bar' style
-         (if (zerop total-playing-time)
-             (setq emms-playing-time-string "[==>........]")
-           (let ((progress "[")
-                 ;; percent based on 10
-                 (percent (/ (* emms-playing-time 10) total-playing-time)))
-             (dotimes (_i percent)
-               (setq progress (concat progress "=")))
-             (setq progress (concat progress ">"))
-             (dotimes (_i (- 10 percent))
-               (setq progress (concat progress " ")))
-             (setq progress (concat progress "]"))
-             (setq emms-playing-time-string progress))))
-        (t                              ; `time' style
-         (setq emms-playing-time-string
-               (emms-replace-regexp-in-string
-                " " "0"
-                (if (or emms-playing-time-display-short-p
-                        ;; unable to get total playing-time
-                        (eq total-playing-time 0))
-                    (format "%2d:%2d" min sec)
-                  (format "%2d:%2d/%2s:%2s"
-                          min sec total-min-only total-sec-only))))))
-      (setq emms-playing-time-string
-            (format emms-playing-time-display-format
-                    emms-playing-time-string))))
+  (setq emms-playing-time-string
+        (if (null emms-playing-time-display-p)
+            ""
+          (let* ((min (/ emms-playing-time 60))
+                 (sec (% emms-playing-time 60))
+                 (total-playing-time
+                  (or (emms-track-get
+                       (emms-playlist-current-selected-track)
+                       'info-playing-time)
+                      0))
+                 (total-min-only (/ total-playing-time 60))
+                 (total-sec-only (% total-playing-time 60))
+                 (string
+	          (cl-case emms-playing-time-style
+	            ((downtime)         ; `downtime' style
+	             (emms-replace-regexp-in-string
+                      " " "0"
+                      (if (or emms-playing-time-display-short-p
+                              ;; unable to get total playing-time
+                              (eq total-playing-time 0))
+                          (format "%2d:%2d" min sec)
+                        (format "-%2d:%2d"
+			        (/ (- total-playing-time emms-playing-time) 60)
+			        (% (- total-playing-time sec) 60)))))
+		    ((bar)              ; `bar' style
+		     (if (zerop total-playing-time)
+		         "[==>........]"
+                       (let (;; percent based on 10
+                             (percent (/ (* emms-playing-time 10)
+                                         total-playing-time)))
+                         (concat "["
+                                 (make-string percent ?=)
+                                 ">"
+                                 (make-string (- 10 percent) ?\s)
+                                 "]"))))
+                    (t                  ; `time' style
+                     (emms-replace-regexp-in-string
+                      " " "0"
+                      (if (or emms-playing-time-display-short-p
+                              ;; unable to get total playing-time
+                              (eq total-playing-time 0))
+                          (format "%2d:%2d" min sec)
+                        (format "%2d:%2d/%2s:%2s"
+                                min sec total-min-only total-sec-only)))))))
+            (format emms-playing-time-display-format string))))
   (force-mode-line-update))
 
 (defun emms-playing-time-mode-line ()
diff --git a/emms-playlist-limit.el b/emms-playlist-limit.el
index 8f274c8..f21f4f8 100644
--- a/emms-playlist-limit.el
+++ b/emms-playlist-limit.el
@@ -178,9 +178,11 @@ is non-nil."
 
 (defun emms-playlist-limit--limit-playlist (playlist type regexp)
   "Return a new playlist of tracks in PLAYLIST with TYPE matching REGEXP."
-  (let* ((bufname (concat (buffer-name playlist)
-			  (format "/%s=%s"
-				  (emms-replace-regexp-in-string "info-" "" (symbol-name type)) regexp))))
+  (let* ((bufname (format "%s/%s=%s"
+			  (buffer-name playlist)
+			  (emms-replace-regexp-in-string "info-" ""
+			                                 (symbol-name type))
+			  regexp)))
     (emms-playlist-limit--derive-playlist
      playlist
      (lambda (track) (let ((field (emms-playlist-limit-track-get track type)))
diff --git a/emms-playlist-mode.el b/emms-playlist-mode.el
index 2815a56..a2aefca 100644
--- a/emms-playlist-mode.el
+++ b/emms-playlist-mode.el
@@ -581,7 +581,7 @@ WINDOW-WIDTH should be a positive integer."
   (setq buffer-undo-list nil))
 
 ;;;###autoload
-(defun emms-playlist-mode ()
+(defun emms-playlist-mode ()            ;FIXME: Use `define-derived-mode'.
   "A major mode for Emms playlists.
 \\{emms-playlist-mode-map}"
   (interactive)
diff --git a/emms-tag-editor.el b/emms-tag-editor.el
index d0028d2..c00a4fb 100644
--- a/emms-tag-editor.el
+++ b/emms-tag-editor.el
@@ -295,6 +295,7 @@ This string is suitable for inserting into the tags buffer."
 
 (defvar emms-tag-editor-mode-map
   (let ((map (make-sparse-keymap)))
+    ;; FIXME: Bind to "\t" rather than [tab] so it works in ttys as well.
     (define-key map [tab] #'emms-tag-editor-next-field)
     (define-key map [backtab] #'emms-tag-editor-prev-field)
     (define-key map "\C-c\C-n" #'emms-tag-editor-next-track)