Reduce usage of cl-* functions

* calibre-cli.el (calibre-cli--get-authors):
  (calibre-cli--get-tags):
  (calibre-cli--get-formats):
* calibre-core.el (calibre--get-filter-items):
  (calibre-library--filter):
* calibre-search.el (calibre-search--operation):

  Replace cl-* functions with equivalent seq-* functions.

calibre-cli.el

@@ -132,9 +132,11 @@ AUTHORS should be a comma separated string."
 (defun calibre-cli--get-authors ()
   "Return a list of the authors in the active library."
   (cl-remove-duplicates
-   (cl-reduce #'cl-union (mapcar (lambda (b)
-                                  (calibre-cli--parse-authors (alist-get 'authors b)))
-                                 (calibre-cli--list "authors")))
+   (seq-reduce #'seq-union
+               (mapcar (lambda (b)
+                         (calibre-cli--parse-authors (alist-get 'authors b)))
+                       (calibre-cli--list "authors"))
+               '())
    :test #'string=))
 
 (defun calibre-cli--get-publishers ()
@@ -155,17 +157,19 @@ AUTHORS should be a comma separated string."
 
 (defun calibre-cli--get-tags ()
   "Return a list of the tags in the active library."
-  (cl-remove-duplicates
-   (cl-reduce #'cl-union (mapcar (lambda (b)
-                                  (alist-get 'tags b))
-                                 (calibre-cli--list "tags")))
-   :test #'string=))
+  (seq-reduce #'seq-union
+               (mapcar (lambda (b)
+                         (alist-get 'tags b))
+                       (calibre-cli--list "tags"))
+               '()))
 
 (defun calibre-cli--get-formats ()
   "Return a list of the file formats stored in the active library."
-  (cl-reduce #'cl-union (mapcar (lambda (b)
-                                  (calibre-cli--parse-formats (alist-get 'formats b)))
-                                (calibre-cli--list "formats"))))
+  (seq-reduce #'seq-union
+              (mapcar (lambda (b)
+                        (calibre-cli--parse-formats (alist-get 'formats b)))
+                      (calibre-cli--list "formats"))
+              '()))
 
 (provide 'calibre-cli)
 ;;; calibre-cli.el ends here

calibre-core.el

@@ -208,12 +208,15 @@ BOOK is a `calibre-book'."
   "Return the id's of books matching FILTER."
   (if (calibre-composite-filter-p filter)
       (seq-let (op filters) filter
-        (cl-reduce (if (eq op '+)
-                       #'cl-union
-                     #'cl-intersection)
-                    (mapcar (lambda (f)
+        (seq-reduce (if (eq op '+)
+                       #'seq-union
+                     #'seq-intersection)
+                   (mapcar (lambda (f)
                              (calibre--get-filter-items (vconcat `[,op] f)))
-                           filters)))
+                           filters)
+                   (if (eq op '+)
+                       '()
+                     (calibre--books))))
     (seq-let (_ field value) filter
       (cl-case field
         (title (calibre-core--interface get-title-books value))
@@ -227,23 +230,25 @@ BOOK is a `calibre-book'."
   "Return those books in BOOKS that match FILTERS.
 FILTERS should be a list of vectors, for the exact contents see
 `calibre-virtual-libraries'."
-  (let* ((include (cl-remove-if-not (lambda (f) (eq (elt f 0) '+)) filters))
-         (exclude (cl-remove-if-not (lambda (f) (eq (elt f 0) '-)) filters))
+  (let* ((include (seq-filter (lambda (f) (eq (elt f 0) '+)) filters))
+         (exclude (seq-filter (lambda (f) (eq (elt f 0) '-)) filters))
          (include-ids (when include
-                        (cl-reduce #'cl-intersection
-                                   (mapcar #'calibre--get-filter-items include))))
+                        (seq-reduce #'seq-intersection
+                                    (mapcar #'calibre--get-filter-items include)
+                                    (mapcar #'calibre-book-id calibre--books))))
          (exclude-ids (when exclude
-                        (cl-reduce #'cl-union
-                                   (mapcar #'calibre--get-filter-items exclude)))))
-    (cl-remove-if (lambda (b)
-                    (seq-find (lambda (id)
-                                (= id (calibre-book-id b)))
-                              exclude-ids))
+                        (seq-reduce #'seq-union
+                                    (mapcar #'calibre--get-filter-items exclude)
+                                    '()))))
+    (seq-filter (lambda (b)
+                  (not (seq-find (lambda (id)
+                                   (= id (calibre-book-id b)))
+                                 exclude-ids)))
                   (if include-ids
-                      (cl-remove-if-not (lambda (b)
-                                      (seq-find (lambda (id)
-                                                  (= id (calibre-book-id b)))
-                                                include-ids))
+                      (seq-filter (lambda (b)
+                                    (seq-find (lambda (id)
+                                                (= id (calibre-book-id b)))
+                                              include-ids))
                                         books)
                     (if include
                         nil

calibre-search.el

@@ -55,7 +55,9 @@ will not be appended to the calibre-db--get-FIELD function's name."
 (defun calibre-search--operation (args)
   "Return the appropriate symbol for a filter operation.
 ARGS is the argument list of a transient command."
-  (if (cl-find "--exclude" args :test #'string=) '- '+))
+  (if (seq-contains-p args "--exclude")
+      '-
+    '+))
 
 (defmacro calibre-library--search-function (field)
   "Create a function adding a filter for FIELD."