Don't use multiline pairs for head/tail modifier.

data/fixtures/recorded/headTail/changeTail3.yml

@@ -0,0 +1,28 @@
+languageId: python
+command:
+  version: 7
+  spokenForm: change tail
+  action:
+    name: clearAndSetSelection
+    target:
+      type: primitive
+      modifiers:
+        - {type: extendThroughEndOf}
+  usePrePhraseSnapshot: true
+initialState:
+  documentContents: |-
+    """foo
+    bar
+    """
+  selections:
+    - anchor: {line: 0, character: 3}
+      active: {line: 0, character: 3}
+  marks: {}
+finalState:
+  documentContents: |-
+    """
+    bar
+    """
+  selections:
+    - anchor: {line: 0, character: 3}
+      active: {line: 0, character: 3}

packages/common/src/types/command/PartialTargetDescriptor.types.ts

@@ -251,6 +251,8 @@ export interface SurroundingPairScopeType {
 export interface SurroundingPairInteriorScopeType {
   type: "surroundingPairInterior";
   delimiter: SurroundingPairName;
+  // If true don't yield multiline pairs
+  requireSingleLine?: boolean;
 }
 
 export interface OneOfScopeType {

packages/cursorless-engine/src/processTargets/modifiers/HeadTailStage.ts

@@ -27,6 +27,7 @@ export class HeadTailStage implements ModifierStage {
             {
               type: "surroundingPairInterior",
               delimiter: "any",
+              requireSingleLine: true,
             },
           ],
         },

packages/cursorless-engine/src/processTargets/modifiers/scopeHandlers/SurroundingPairScopeHandler/SurroundingPairInteriorScopeHandler.ts

@@ -5,7 +5,6 @@ import type { TargetScope } from "../scope.types";
 import type { ScopeIteratorRequirements } from "../scopeHandler.types";
 import { type ScopeHandler } from "../scopeHandler.types";
 import type { ScopeHandlerFactory } from "../ScopeHandlerFactory";
-import { map } from "itertools";
 
 export class SurroundingPairInteriorScopeHandler extends BaseScopeHandler {
   protected isHierarchical = true;
@@ -32,28 +31,31 @@ export class SurroundingPairInteriorScopeHandler extends BaseScopeHandler {
     return this.surroundingPairScopeHandler.iterationScopeType;
   }
 
-  generateScopeCandidates(
+  *generateScopeCandidates(
     editor: TextEditor,
     position: Position,
     direction: Direction,
     hints: ScopeIteratorRequirements,
   ): Iterable<TargetScope> {
-    return map(
-      this.surroundingPairScopeHandler.generateScopes(
-        editor,
-        position,
-        direction,
-        hints,
-      ),
-      (scope) => ({
-        editor,
-        domain: scope.domain,
-        getTargets(isReversed) {
-          return scope
-            .getTargets(isReversed)
-            .flatMap((target) => target.getInterior()!);
-        },
-      }),
+    const scopes = this.surroundingPairScopeHandler.generateScopes(
+      editor,
+      position,
+      direction,
+      hints,
     );
+
+    for (const scope of scopes) {
+      if (!this.scopeType.requireSingleLine || scope.domain.isSingleLine) {
+        yield {
+          editor,
+          domain: scope.domain,
+          getTargets(isReversed) {
+            return scope
+              .getTargets(isReversed)
+              .flatMap((target) => target.getInterior()!);
+          },
+        };
+      }
+    }
   }
 }