     parseTest(#"\11"#, scalar("\u{9}"))
     parseTest(
       String(repeating: "()", count: 11) + #"\11"#,
-      concat((0..<11).map { _ in capture(empty()) }
+      concat(Array(repeating: capture(empty()), count: 11)
              + [backreference(.absolute(11))]),
       captures: .tuple(Array(repeating: .atom(), count: 11))
     )
     parseTest(#"\011"#, scalar("\u{9}"))
     parseTest(
       String(repeating: "()", count: 11) + #"\011"#,
-      concat((0..<11).map { _ in capture(empty()) } + [scalar("\u{9}")]),
+      concat(Array(repeating: capture(empty()), count: 11) + [scalar("\u{9}")]),
       captures: .tuple(Array(repeating: .atom(), count: 11))
     )
 


    parseTest(
      #"()()()()()()()()()()\10"#,
      concat((0..<10).map { _ in capture(empty()) }
             + [backreference(.absolute(10))]),
      captures: .tuple(Array(repeating: .atom(), count: 10))
    )
    parseTest(
      #"()()()()()()()()()\10()"#,
      concat((0..<9).map { _ in capture(empty()) }
             + [scalar("\u{8}"), capture(empty())]),
      captures: .tuple(Array(repeating: .atom(), count: 10))
    )

    parseTest(#"\08"#, concat(scalar("\u{0}"), "8"))
    parseTest(#"\0707"#, concat(scalar("\u{38}"), "7"))

    parseTest(#"[\0]"#, charClass(scalar_m("\u{0}")))
    parseTest(#"[\01]"#, charClass(scalar_m("\u{1}")))
    parseTest(#"[\070]"#, charClass(scalar_m("\u{38}")))

    parseTest(#"[\07A]"#, charClass(scalar_m("\u{7}"), "A"))
    parseTest(#"[\08]"#, charClass(scalar_m("\u{0}"), "8"))
