More work, now on merge-tocs

1 files changed, 48 insertions, 18 deletions

diff --git a/src/unheard/time_object.clj b/src/unheard/time_object.clj
index 6f088b6..3556321 100644
--- a/src/unheard/time_object.clj
+++ b/src/unheard/time_object.clj
@@ -37,21 +37,18 @@
   time tree is consumed at a point in time within the time-object's
   interval."
   [>start >end >metadata >flow]
-  (let [action (atom nil)
-        >action (m/watch action)
-        id (swap! id-counter inc)]
-    (m/ap
-     (reset! action
-             [:add
-              id
-              {:start >start
-               :end >end
-               :metadata >metadata
-
-               :flow >flow}])
-     (try
-       (m/?< >action)
-       (catch missionary.Cancelled _ [:remove id])))))
+  (m/ap
+   (let [id (swap! id-counter inc)]
+     (m/amb=
+      [id
+       :add
+       {:start >start
+        :end >end
+        :metadata >metadata
+        :flow >flow}]
+      (try
+        (m/? m/never)
+        (catch missionary.Cancelled _ [id :remove]))))))
 
 (comment
   (def cancel
@@ -60,6 +57,20 @@
 
   (cancel))
 
+(defn with-final
+  []
+  (m/ap
+   (m/amb=
+    :start
+    (try
+      (m/? m/never)
+      (catch missionary.Cancelled _ :end)))))
+
+(defn merge-flows [& flows]
+  (m/ap
+   (m/?<
+    (m/?> (count flows) (m/seed flows)))))
+
 (defn time-object-collection
   "Takes a flow of [diff-action time-object-id time-object], where:
   - diff-action is one of either :add or :remove
@@ -68,14 +79,16 @@
 
   Returns a collection of time objects, represented as a flow."
   [& time-objects]
-  (apply m/latest vector time-objects))
+  ;; Goal: use group-by to emit just twice per time object
+  (m/ap (m/?>  (try (apply m/zip vector time-objects) (catch missionary.Cancelled _)))))
 
 (comment
   (def cancel
     ((m/reduce prn nil
                (time-object-collection
                 (time-object 1 2 :a (m/ap))
-                (time-object 3 4 :a (m/ap)))) prn prn))
+                (time-object 3 4 :b (m/ap))
+                (time-object 5 6 :c (m/ap)))) prn prn))
 
   (cancel))
 
@@ -84,7 +97,24 @@
 
 (defn merge-tocs
   "Merge multiple time-object-collections. Returns a new time-object-collection."
-  [& time-object-colletion])
+  [& time-object-collections]
+  (apply merge-flows time-object-collections))
+
+(comment
+  (def cancel
+    ((m/reduce prn nil
+               (merge-tocs
+                (time-object-collection
+                 (time-object 1 2 :a (m/ap))
+                 (time-object 3 4 :b (m/ap))
+                 (time-object 5 6 :c (m/ap)))
+                (time-object-collection
+                 (time-object 1 2 :d (m/ap))
+                 (time-object 3 4 :e (m/ap))
+                 (time-object 5 6 :f (m/ap))))) prn prn))
+  ;; Whoa! Running cancel twice cancels twice...
+  ;; https://clojurians.slack.com/archives/CL85MBPEF/p1763154775780589?thread_ts=1763149125.436899&cid=CL85MBPEF
+  (cancel))
 
 (defn timeline
   "Primary timeline bookkeeping mehanism."