Update sidechain references after topology change.

vite/src/pipedal/Pedalboard.tsx

@@ -394,6 +394,7 @@ export class Pedalboard implements Deserializable<Pedalboard> {
     pathProperties: {[Name: string]: string} = {};
     selectedPlugin: number = -1;
 
+    // yields all items in the pedalboard, including split items. Splits are yielded before their children.
     *itemsGenerator(): Generator<PedalboardItem, void, undefined> {
         let it = itemGenerator_(this.items);
         while (true)
@@ -403,6 +404,16 @@ export class Pedalboard implements Deserializable<Pedalboard> {
             yield v.value;
         }
     }
+    // same as itemsGenerator, but yields split items after their chains.
+    *itemsGeneratorSplitAfter(): Generator<PedalboardItem, void, undefined> {
+        let it = itemGeneratorSplitAfter_(this.items);
+        while (true)
+        {
+            let v = it.next();
+            if (v.done) break;
+            yield v.value;
+        }
+    }
 
     makeSnapshot(): Snapshot {
         let result = new Snapshot();
@@ -793,4 +804,28 @@ function* itemGenerator_(items: PedalboardItem[]): Generator<PedalboardItem, voi
     }
 }
 
+function* itemGeneratorSplitAfter_(items: PedalboardItem[]): Generator<PedalboardItem, void, undefined> {
+    for (let i = 0; i < items.length; ++i) {
+        let item = items[i];
+        if (item.uri === SPLIT_PEDALBOARD_ITEM_URI) {
+
+            let splitItem = item as PedalboardSplitItem;
+
+            let it = itemGenerator_(splitItem.topChain);
+            while (true) {
+                let v = it.next();
+                if (v.done) break;
+                yield v.value;
+            }
+            it = itemGenerator_(splitItem.bottomChain);
+            while (true) {
+                let v = it.next();
+                if (v.done) break;
+                yield v.value;
+            }
+        }
+        yield item;
+    }
+}
+