Optimized performance in bounded scope handler

Author: AndreasArvidsson

packages/cursorless-engine/src/processTargets/modifiers/scopeHandlers/BoundedScopeHandler.ts

@@ -100,13 +100,18 @@ abstract class BoundedBaseScopeHandler extends BaseScopeHandler {
       ),
     );
 
+    if (interiorScopes.length === 0) {
+      yield* targetScopes;
+      return;
+    }
+
     for (const targetScope of targetScopes) {
-      const allScopes: TargetScope[] = [];
+      let allScopes: TargetScope[] | undefined;
 
       for (const interiorScope of interiorScopes) {
         const domain = targetScope.domain.intersection(interiorScope.domain);
         if (domain != null && !domain.isEmpty) {
-          allScopes.push({
+          (allScopes ??= []).push({
             editor,
             domain,
             getTargets: (isReversed) => {
@@ -121,6 +126,30 @@ abstract class BoundedBaseScopeHandler extends BaseScopeHandler {
         }
       }
 
+      if (allScopes == null) {
+        yield targetScope;
+        continue;
+      }
+
+      if (allScopes.length === 1) {
+        const intersectionScope = allScopes[0];
+        if (
+          compareTargetScopes(
+            direction,
+            position,
+            intersectionScope,
+            targetScope,
+          ) <= 0
+        ) {
+          yield intersectionScope;
+          yield targetScope;
+        } else {
+          yield targetScope;
+          yield intersectionScope;
+        }
+        continue;
+      }
+
       // NB: We add the target scope last so that if it is identical to
       // one of our intersection scopes, we prefer that one so that rich ranges
       // function properly
@@ -162,7 +191,7 @@ export class BoundedNonWhitespaceSequenceScopeHandler extends BoundedBaseScopeHa
     );
 
     if (contentRange == null || contentRange.isEmpty) {
-      throw Error("Expected non empty intersection");
+      throw Error("Expected non-empty intersection");
     }
 
     return new TokenTarget({