Prevent overlapping pairs

data/fixtures/scopes/textual/surroundingPair4.scope

@@ -0,0 +1,44 @@
+(a < b)
+(c > d)
+---
+
+[#1 Content] =
+[#1 Removal] =
+[#1 Domain] = 0:0-0:7
+  >-------<
+0| (a < b)
+
+[#1 Interior] = 0:1-0:6
+   >-----<
+0| (a < b)
+
+[#1 Boundary L] = 0:0-0:1
+  >-<
+0| (a < b)
+
+[#1 Boundary R] = 0:6-0:7
+        >-<
+0| (a < b)
+
+[#1 Insertion delimiter] = " "
+
+
+[#2 Content] =
+[#2 Removal] =
+[#2 Domain] = 1:0-1:7
+  >-------<
+1| (c > d)
+
+[#2 Interior] = 1:1-1:6
+   >-----<
+1| (c > d)
+
+[#2 Boundary L] = 1:0-1:1
+  >-<
+1| (c > d)
+
+[#2 Boundary R] = 1:6-1:7
+        >-<
+1| (c > d)
+
+[#2 Insertion delimiter] = " "

data/fixtures/scopes/textual/surroundingPair5.scope

@@ -0,0 +1,38 @@
+(  [  )  ]
+---
+
+[Content] =
+[Domain] = 0:0-0:7
+  >-------<
+0| (  [  )  ]
+
+[Removal] = 0:0-0:9
+  >---------<
+0| (  [  )  ]
+
+[Trailing delimiter] = 0:7-0:9
+         >--<
+0| (  [  )  ]
+
+[Interior: Content] = 0:3-0:4
+     >-<
+0| (  [  )  ]
+[Interior: Removal] = 0:1-0:6
+   >-----<
+0| (  [  )  ]
+
+[Boundary L: Content] = 0:0-0:1
+  >-<
+0| (  [  )  ]
+[Boundary L: Removal] = 0:0-0:3
+  >---<
+0| (  [  )  ]
+
+[Boundary R: Content] = 0:6-0:7
+        >-<
+0| (  [  )  ]
+[Boundary R: Removal] = 0:6-0:9
+        >---<
+0| (  [  )  ]
+
+[Insertion delimiter] = " "

data/fixtures/scopes/textual/surroundingPair6.scope

@@ -0,0 +1,22 @@
+([)]
+---
+
+[Content] =
+[Removal] =
+[Domain] = 0:0-0:3
+  >---<
+0| ([)]
+
+[Interior] = 0:1-0:2
+   >-<
+0| ([)]
+
+[Boundary L] = 0:0-0:1
+  >-<
+0| ([)]
+
+[Boundary R] = 0:2-0:3
+    >-<
+0| ([)]
+
+[Insertion delimiter] = " "

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

@@ -1,5 +1,5 @@
-import type { SimpleSurroundingPairName } from "@cursorless/common";
-import { DefaultMap } from "@cursorless/common";
+import type { Range } from "@cursorless/common";
+import findLastIndex from "lodash-es/findLastIndex";
 import type { DelimiterOccurrence, SurroundingPairOccurrence } from "./types";
 
 /**
@@ -13,14 +13,7 @@ export function getSurroundingPairOccurrences(
   delimiterOccurrences: DelimiterOccurrence[],
 ): SurroundingPairOccurrence[] {
   const result: SurroundingPairOccurrence[] = [];
-
-  /**
-   * A map from delimiter names to occurrences of the opening delimiter
-   */
-  const openingDelimiterOccurrences = new DefaultMap<
-    SimpleSurroundingPairName,
-    DelimiterOccurrence[]
-  >(() => []);
+  const openingDelimitersStack: DelimiterOccurrence[] = [];
 
   for (const occurrence of delimiterOccurrences) {
     const {
@@ -29,48 +22,29 @@ export function getSurroundingPairOccurrences(
       range,
     } = occurrence;
 
-    let openingDelimiters = openingDelimiterOccurrences.get(delimiterName);
-
-    if (isSingleLine) {
-      // If single line, remove all opening delimiters that are not on the same line
-      // as occurrence
-      openingDelimiters = openingDelimiters.filter(
-        (openingDelimiter) =>
-          openingDelimiter.range.start.line === range.start.line,
-      );
-      openingDelimiterOccurrences.set(delimiterName, openingDelimiters);
-    }
-
-    /**
-     * A list of opening delimiters that are relevant to the current occurrence.
-     * We exclude delimiters that are not in the same text fragment range as the
-     * current occurrence.
-     */
-    const relevantOpeningDelimiters = openingDelimiters.filter(
-      (openingDelimiter) =>
-        (textFragmentRange == null &&
-          openingDelimiter.textFragmentRange == null) ||
-        (textFragmentRange != null &&
-          openingDelimiter.textFragmentRange != null &&
-          openingDelimiter.textFragmentRange.isRangeEqual(textFragmentRange)),
-    );
-
-    if (
-      side === "left" ||
-      (side === "unknown" && relevantOpeningDelimiters.length % 2 === 0)
-    ) {
-      openingDelimiters.push(occurrence);
+    if (side === "left") {
+      openingDelimitersStack.push(occurrence);
     } else {
-      const openingDelimiter = relevantOpeningDelimiters.at(-1);
+      const openingDelimiterIndex = findLastIndex(
+        openingDelimitersStack,
+        (o) =>
+          o.delimiterInfo.delimiterName === delimiterName &&
+          isSameTextFragment(o.textFragmentRange, textFragmentRange) &&
+          isValidLine(isSingleLine, o.range, range),
+      );
 
-      if (openingDelimiter == null) {
+      if (openingDelimiterIndex === -1) {
+        // When side is unknown and we can't find an opening delimiter, that means this is the opening delimiter.
+        if (side === "unknown") {
+          openingDelimitersStack.push(occurrence);
+        }
         continue;
       }
 
-      openingDelimiters.splice(
-        openingDelimiters.lastIndexOf(openingDelimiter),
-        1,
-      );
+      const openingDelimiter = openingDelimitersStack[openingDelimiterIndex];
+
+      // Pop stack up to and including the opening delimiter
+      openingDelimitersStack.length = openingDelimiterIndex;
 
       result.push({
         delimiterName: delimiterName,
@@ -82,3 +56,17 @@ export function getSurroundingPairOccurrences(
 
   return result;
 }
+
+function isSameTextFragment(
+  a: Range | undefined,
+  b: Range | undefined,
+): boolean {
+  if (a == null || b == null) {
+    return a === b;
+  }
+  return a.isRangeEqual(b);
+}
+
+function isValidLine(isSingleLine: boolean, a: Range, b: Range): boolean {
+  return !isSingleLine || a.start.line === b.start.line;
+}