Update filling functionality.

`fill-paragraph`, `fill-region`, and `auto-fill-mode` parse
comments and multline strings as KDoc markdown and fill paragraphs with
appropriate prefix (combination of `/`, `*`, `>`, and indentation).

Example:

```kotlin
/**
 *
 * *  >>  -  >10.  2)  aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *    >>     >         aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *    >>     >         aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *
 * @param foo  aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *     aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *     aaa aaa aaa
 * @param bar
 *     aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *     aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
 *     aaa
 */
```

kotlin-mode-lexer.el

@@ -354,6 +354,15 @@ It have the type and the start position.")
   "Return the start position of the CHUNK."
   (and chunk (oref chunk start)))
 
+(defun kotlin-mode--chunk-end (chunk)
+  "Return the end position of the CHUNK."
+  (save-excursion
+    (goto-char (oref chunk start))
+    (if (kotlin-mode--chunk-comment-p chunk)
+        (forward-comment 1)
+      (kotlin-mode--forward-token))
+    (point)))
+
 (defun kotlin-mode--chunk-comment-p (chunk)
   "Return non-nil if the CHUNK is a comment."
   (and chunk
@@ -455,6 +464,17 @@ If PARSER-STATE is given, it is used instead of (syntax-ppss)."
      (t
       nil))))
 
+(defun kotlin-mode--chunk-after-spaces ()
+  "Return the chunk at the point or after spaces.
+
+If there is no chunk at the point nor after spaces, return nil."
+  (or (kotlin-mode--chunk-after)
+      (save-excursion
+        (skip-chars-forward " ")
+        (when (memq (char-after) '(?\" ?/))
+          (forward-char)
+          (kotlin-mode--chunk-after)))))
+
 ;; Syntax table
 
 (defvar kotlin-mode-syntax-table
@@ -2584,6 +2604,17 @@ Newlines inside comments are ignored."
                 (forward-comment (- (point)))
                 (point)))))
 
+(defun kotlin-mode--same-line-p (point1 point2)
+  "Return non-nil if POINT1 and POINT2 is on the same line.
+
+Return nil otherwise."
+  (= (save-excursion
+       (goto-char point1)
+       (line-beginning-position))
+     (save-excursion
+       (goto-char point2)
+       (line-beginning-position))))
+
 (provide 'kotlin-mode-lexer)
 
 ;;; kotlin-mode-lexer.el ends here

kotlin-mode.el

@@ -35,6 +35,7 @@
 
 (require 'kotlin-mode-lexer)
 (require 'kotlin-mode-indent)
+(require 'kotlin-mode-fill)
 
 (defgroup kotlin nil
   "A Kotlin major mode."
@@ -358,18 +359,17 @@ and return non-nil.  Return nil otherwise."
                         ;; Multi-line comment
                         (seq "/" (one-or-more "*"))
                         ;; Middle of multi-line-comment
-                        (seq (one-or-more "*") " "))
+                        (seq (one-or-more "*") (zero-or-one " ")))
                        (zero-or-more (syntax whitespace)))))
-  (setq-local adaptive-fill-regexp
-              (rx (seq (zero-or-more (syntax whitespace))
-                       (or
-                        ;; Single-line comment
-                        (seq "/" (one-or-more "/"))
-                        ;; Middle of multi-line-comment
-                        (seq (one-or-more "*") " "))
-                       (zero-or-more (syntax whitespace)))))
-  (setq-local fill-indent-according-to-mode t)
+  (setq-local adaptive-fill-first-line-regexp ".*")
+  (setq-local adaptive-fill-function #'kotlin-mode--adaptive-fill)
+  (setq-local fill-indent-according-to-mode nil)
   (setq-local comment-multi-line t)
+  (setq-local fill-paragraph-function #'kotlin-mode--fill-paragraph)
+  (setq-local fill-forward-paragraph-function
+              #'kotlin-mode--fill-forward-paragraph)
+  (setq-local normal-auto-fill-function #'kotlin-mode--do-auto-fill)
+  (kotlin-mode--install-fill-region-as-paragraph-advice)
 
   (setq-local indent-line-function 'kotlin-mode--indent-line)
 

scripts/run_linter.sh

@@ -14,6 +14,6 @@ rm -f *-autoloads.el || exit 1
   -l elisp-lint.el \
   --eval '(setq elisp-lint--debug t)' \
   -f elisp-lint-files-batch \
-  *.el || exit 1
+  *.el "$@" || exit 1
 rm -f *.elc test/*.elc || exit 1
 rm -f *-autoloads.el || exit 1

scripts/run_linter_in_docker.sh

@@ -5,6 +5,7 @@
 # Cask does't support Emacs 24.
 for version in 28 27 26 25 # 24
 do
+    ARGS=$( [ "$version" -lt 26 ] && echo "--no-checkdoc" )
     docker \
         run \
         --rm \
@@ -13,8 +14,8 @@ do
         --workdir="/src" \
         --env=ELDEV_DIR=/src/.eldev \
         --env=HOME=/tmp \
-        silex/emacs:${version} \
-        bash -c "/src/scripts/run_linter.sh" \
+        silex/emacs:${version}-ci \
+        bash -c "/src/scripts/run_linter.sh $ARGS" \
         || exit 1
 done
 

scripts/run_test_in_docker.sh

@@ -15,7 +15,7 @@ do
         --workdir="/src" \
         --env=ELDEV_DIR=/src/.eldev \
         --env=HOME=/tmp \
-        silex/emacs:${version} \
+        silex/emacs:${version}-ci \
         bash -c "/src/scripts/run_test.sh" \
         || exit 1
 done