bench: add Realistic10 (10% quoted) benchmark case (#90)

Author: nnnkkk7

benchmark_test.go

@@ -139,6 +139,30 @@ func BenchmarkReadAll_Quoted_100K_SIMD(b *testing.B) {
 	}
 }
 
+// =============================================================================
+// ReadAll Benchmarks - Realistic CSV (10% quoted)
+// =============================================================================
+
+func BenchmarkReadAll_Realistic10_100K_Stdlib(b *testing.B) {
+	data := generateRealistic10CSV(100000, 10)
+	b.SetBytes(int64(len(data)))
+	for b.Loop() {
+		reader := csv.NewReader(bytes.NewReader(data))
+		reader.FieldsPerRecord = -1
+		_, _ = reader.ReadAll()
+	}
+}
+
+func BenchmarkReadAll_Realistic10_100K_SIMD(b *testing.B) {
+	data := generateRealistic10CSV(100000, 10)
+	b.SetBytes(int64(len(data)))
+	for b.Loop() {
+		reader := NewReader(bytes.NewReader(data))
+		reader.FieldsPerRecord = -1
+		_, _ = reader.ReadAll()
+	}
+}
+
 // =============================================================================
 // ReadAll Benchmarks - Realistic CSV (20% quoted)
 // =============================================================================

test_helpers_test.go

@@ -203,6 +203,18 @@ func generateEscapedQuotesCSV(numRows, numCols int) []byte {
 	return buf.Bytes()
 }
 
+// generateRealistic10CSV generates CSV with 1/10 quoted fields containing commas (~10%).
+// Row template: "Alice, Smith",30,Tokyo,engineer,100,Japan,active,42,NewYork,2024
+// Col 0 is quoted.
+func generateRealistic10CSV(numRows, _ int) []byte {
+	var buf bytes.Buffer
+	for i := 0; i < numRows; i++ {
+		buf.WriteString(`"Alice, Smith",30,Tokyo,engineer,100,Japan,active,42,NewYork,2024`)
+		buf.WriteByte('\n')
+	}
+	return buf.Bytes()
+}
+
 // generateRealistic20CSV generates CSV with 2/10 quoted fields containing commas (~20%).
 // Row template: "Alice, Smith",30,Tokyo,engineer,100,Japan,active,42,"New York, US",2024
 // Cols 0,8 are quoted.