Change implementation of default bounded line for head/tail modifiers (#2799)

Today's implementation is too quirky with its single versus multiline
behavior. I have multiple times gotten an unexpected behavior.

## Checklist

- [x] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [x] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [/] I have not broken the cheatsheet

---------

Co-authored-by: Phil Cohen <[email protected]>

Author: AndreasArvidsson

data/fixtures/recorded/headTail/changeHead3.yml

@@ -0,0 +1,26 @@
+languageId: plaintext
+command:
+  version: 7
+  spokenForm: change head
+  action:
+    name: clearAndSetSelection
+    target:
+      type: primitive
+      modifiers:
+        - {type: extendThroughStartOf}
+  usePrePhraseSnapshot: false
+initialState:
+  documentContents: |-
+    (aaa
+    )
+  selections:
+    - anchor: {line: 0, character: 4}
+      active: {line: 0, character: 4}
+  marks: {}
+finalState:
+  documentContents: |-
+    (
+    )
+  selections:
+    - anchor: {line: 0, character: 1}
+      active: {line: 0, character: 1}

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

@@ -253,8 +253,6 @@ 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

@@ -1,12 +1,17 @@
-import type { HeadModifier, Modifier, TailModifier } from "@cursorless/common";
+import {
+  NoContainingScopeError,
+  type HeadModifier,
+  type ScopeType,
+  type TailModifier,
+} from "@cursorless/common";
 import type { Target } from "../../typings/target.types";
 import type { ModifierStageFactory } from "../ModifierStageFactory";
 import type { ModifierStage } from "../PipelineStages.types";
 import {
   getModifierStagesFromTargetModifiers,
   processModifierStages,
 } from "../TargetPipelineRunner";
-import { HeadTailTarget } from "../targets";
+import { HeadTailTarget, PlainTarget } from "../targets";
 
 export class HeadTailStage implements ModifierStage {
   constructor(
@@ -15,34 +20,11 @@ export class HeadTailStage implements ModifierStage {
   ) {}
 
   run(target: Target): Target[] {
-    const modifiers: Modifier[] = this.modifier.modifiers ?? [
-      {
-        type: "containingScope",
-        scopeType: {
-          type: "oneOf",
-          scopeTypes: [
-            {
-              type: "line",
-            },
-            {
-              type: "surroundingPairInterior",
-              delimiter: "any",
-              requireSingleLine: true,
-            },
-          ],
-        },
-      },
-    ];
-
-    const modifierStages = getModifierStagesFromTargetModifiers(
-      this.modifierStageFactory,
-      modifiers,
-    );
+    const modifierStages = this.getModifierStages();
     const modifiedTargets = processModifierStages(modifierStages, [target]);
+    const isHead = this.modifier.type === "extendThroughStartOf";
 
     return modifiedTargets.map((modifiedTarget) => {
-      const isHead = this.modifier.type === "extendThroughStartOf";
-
       return new HeadTailTarget({
         editor: target.editor,
         isReversed: isHead,
@@ -52,4 +34,70 @@ export class HeadTailStage implements ModifierStage {
       });
     });
   }
+
+  private getModifierStages(): ModifierStage[] {
+    if (this.modifier.modifiers != null) {
+      return getModifierStagesFromTargetModifiers(
+        this.modifierStageFactory,
+        this.modifier.modifiers,
+      );
+    }
+
+    return [new BoundedLineStage(this.modifierStageFactory, this.modifier)];
+  }
+}
+
+class BoundedLineStage implements ModifierStage {
+  constructor(
+    private modifierStageFactory: ModifierStageFactory,
+    private modifier: HeadModifier | TailModifier,
+  ) {}
+
+  run(target: Target): Target[] {
+    const line = this.getContainingLine(target);
+    const pairInterior = this.getContainingPairInterior(target);
+
+    const intersection =
+      pairInterior != null
+        ? line.contentRange.intersection(pairInterior.contentRange)
+        : null;
+
+    if (intersection == null || intersection.isEmpty) {
+      return [line];
+    }
+
+    return [
+      new PlainTarget({
+        editor: target.editor,
+        isReversed: target.isReversed,
+        contentRange: intersection,
+      }),
+    ];
+  }
+
+  private getContainingPairInterior(target: Target): Target | undefined {
+    try {
+      return this.getContaining(target, {
+        type: "surroundingPairInterior",
+        delimiter: "any",
+      })[0];
+    } catch (error) {
+      if (error instanceof NoContainingScopeError) {
+        return undefined;
+      }
+      throw error;
+    }
+  }
+
+  private getContainingLine(target: Target): Target {
+    return this.getContaining(target, {
+      type: "line",
+    })[0];
+  }
+
+  private getContaining(target: Target, scopeType: ScopeType): Target[] {
+    return this.modifierStageFactory
+      .create({ type: "containingScope", scopeType })
+      .run(target);
+  }
 }

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

@@ -45,10 +45,6 @@ export class SurroundingPairInteriorScopeHandler extends BaseScopeHandler {
     );
 
     for (const scope of scopes) {
-      if (this.scopeType.requireSingleLine && !scope.domain.isSingleLine) {
-        continue;
-      }
-
       yield {
         editor,
         domain: scope.domain,

packages/cursorless-org-docs/src/docs/user/README.md

@@ -314,7 +314,7 @@ The modifiers `"head"` and `"tail"` can be used to expand a target through the b
 - `"take head air"`: selects the mark through to start of the line
 - `"take tail air"`: selects the mark through to the end of the line
 
-When inside a single-line surrounding pair (eg parentheses, brackets, etc) the head/tail modifier will only expand to the interior of that pair instead of the whole line. You can explicitly say `"head line"` or `"tail line"` to get the line behavior.
+When inside a surrounding pair (eg parentheses, brackets, etc) the head/tail modifier will only expand to the interior of that pair instead of the whole line. You can explicitly say `"head line"` or `"tail line"` to get the line behavior.
 
 When followed by a modifier, they will expand their input to the start or end of the given modifier range. For example: