perf: allow FASS strides on nested homogeneous object arrays

Stop disabling equal-size array strides when elements contain nested
object-arrays. Confirm+landing skipContainer checks already prevent false
jumps; GitHub-style issues[].labels[] can now stride like flat user lists.

Author: shiaho777

navigate.go

@@ -249,34 +249,6 @@ func firstKeyEqual(data []byte, obj int, ks, ke int) bool {
 	return true
 }
 
-func hasNestedObjectArray(data []byte, start, end int) bool {
-	i := start + 1
-	for i < end {
-		c := data[i]
-		if c == '"' {
-			e, ok := skipStringBody(data, i+1)
-			if !ok || e > end {
-				return false
-			}
-			i = e
-			continue
-		}
-		if c == '[' {
-			j := i + 1
-			for j < end {
-				cj := data[j]
-				if cj == ' ' || cj == 9 || cj == 10 || cj == 13 {
-					j++
-					continue
-				}
-				return cj == '{'
-			}
-			return false
-		}
-		i++
-	}
-	return false
-}
 func strideObject(data []byte, i, lastLen, nlen int, ks, ke int, haveKey bool) (int, bool) {
 	if lastLen < 2 {
 		return i, false
@@ -494,7 +466,7 @@ func findIndexObjectStride(data []byte, i, n, nlen int) (int, bool) {
 				}
 			}
 			if !strideOK && lastLen > 0 {
-				strideOK = !hasNestedObjectArray(data, start, start+lastLen)
+				strideOK = true
 			}
 		}
 		if i >= nlen {

navigate_stride_test.go

@@ -164,3 +164,37 @@ func TestFindIndexStrideRejectsFalseEqualSize(t *testing.T) {
 		t.Fatalf("valid equal-size still works: %q %v", v, err)
 	}
 }
+
+func TestFindIndexStrideGitHubLikeIssues(t *testing.T) {
+	var b strings.Builder
+	b.WriteByte('[')
+	for i := 0; i < 120; i++ {
+		if i > 0 {
+			b.WriteByte(',')
+		}
+		fmt.Fprintf(&b, `{"id":%d,"number":%d,"title":"Issue number %d","state":"open",`, 1000+i, i, i)
+		fmt.Fprintf(&b, `"user":{"login":"user%d","id":%d,"type":"User"},`, i, 2000+i)
+		fmt.Fprintf(&b, `"labels":[{"id":%d,"name":"bug","color":"f29513"},{"id":%d,"name":"help wanted","color":"159818"}],`, i, i+1)
+		fmt.Fprintf(&b, `"comments":%d,"body":"body %d"}`, i%30, i)
+	}
+	b.WriteByte(']')
+	data := []byte(b.String())
+	for _, n := range []int{0, 1, 9, 10, 50, 99, 100, 119} {
+		v, _, _, err := Get(data, "["+strconv.Itoa(n)+"]", "title")
+		if err != nil {
+			t.Fatalf("n=%d: %v", n, err)
+		}
+		want := "Issue number " + strconv.Itoa(n)
+		if string(v) != want {
+			t.Fatalf("n=%d title=%q want %q", n, v, want)
+		}
+		u, _, _, err := Get(data, "["+strconv.Itoa(n)+"]", "user", "login")
+		if err != nil || string(u) != "user"+strconv.Itoa(n) {
+			t.Fatalf("n=%d user=%q err=%v", n, u, err)
+		}
+		lab, _, _, err := Get(data, "["+strconv.Itoa(n)+"]", "labels", "[1]", "name")
+		if err != nil || string(lab) != "help wanted" {
+			t.Fatalf("n=%d label=%q err=%v", n, lab, err)
+		}
+	}
+}