[Timeline] Extract gap-filling into separate function

site-lisp/timeline-tools.el

@@ -44,7 +44,7 @@
   :group 'applications)
 
 (defcustom timeline-tools-filter-functions
-  (list #'timeline-tools-remove-short-entries
+  (list #'timeline-tools-fill-gaps
         #'timeline-tools-cluster-same-entries)
   "List of functions to apply when formatting timelines.
 Filter are applied in the order they are given in this list."
@@ -332,7 +332,9 @@ function will throw an error."
 A slot is short if it is not longer than THRESHOLD seconds.
 Resulting gaps are distributed evenly among adjacent slots.
 THRESHOLD defaults to the value of
-`timeline-tools-short-task-threshold’ if not supplied."
+`timeline-tools-short-task-threshold’ if not supplied.
+
+This function destructively modifies its first argument."
   (unless (null timeline)
     (let ((start (timeline-tools-entry-start-time (-first-item timeline)))
           (end   (timeline-tools-entry-end-time (-last-item timeline)))
@@ -352,9 +354,18 @@ THRESHOLD defaults to the value of
       (setf (timeline-tools-entry-end-time (-last-item new-timeline)) end)
 
       ;; distribute gaps evenly among adjacent slots
+      (timeline-tools-fill-gaps new-timeline))))
+
+(defun timeline-tools-fill-gaps (timeline)
+  "Fill gaps in TIMELINE evenly.
+
+This is achieved by extending the start time and the end time of
+the surrounding entries equally.
+
+This function destructively modifies its first argument."
   (cl-do
-         ((sub-timeline new-timeline (cdr sub-timeline)))
-         ((null (cdr sub-timeline)))
+      ((sub-timeline timeline (cdr sub-timeline)))
+      ((null (cdr sub-timeline)) timeline)
     (let* ((entry-1 (-first-item sub-timeline))
            (entry-2 (-second-item sub-timeline))
            (end-1   (timeline-tools-entry-end-time entry-1))
@@ -362,9 +373,7 @@ THRESHOLD defaults to the value of
       (when (not (= end-1 start-2))
         (let ((middle (/ (+ end-1 start-2) 2)))
           (setf (timeline-tools-entry-end-time entry-1) middle)
-             (setf (timeline-tools-entry-start-time entry-2) middle)))))
-
-     new-timeline)))
+          (setf (timeline-tools-entry-start-time entry-2) middle))))))
 
 (defun timeline-tools-transform-timeline (timeline)
   "Return timeline from files, after application of