     parseTest(#"\040"#, scalar(" "))
     parseTest(
       String(repeating: "()", count: 40) + #"\040"#,
-      concat((0..<40).map { _ in capture(empty()) } + [scalar(" ")]),
+      concat(Array(repeating: capture(empty()), count: 40) + [scalar(" ")]),
       captures: .tuple(Array(repeating: .atom(), count: 40))
     )
     parseTest(#"\40"#, scalar(" "))
     parseTest(
       String(repeating: "()", count: 40) + #"\40"#,
-      concat((0..<40).map { _ in capture(empty()) }
+      concat(Array(repeating: capture(empty()), count: 40)
              + [backreference(.absolute(40))]),
       captures: .tuple(Array(repeating: .atom(), count: 40))
     )

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


    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"))
