Implement missing functions on ListBase.

tests/corelib/string_codeunits_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 main() {
   test(String s) {
     Iterable<int> units = s.codeUnits;
     List<int> expectedUnits = <int>[];
     for (int i = 0; i < s.length; i++) {
       expectedUnits.add(s.codeUnitAt(i));
     }
 
     Expect.equals(s.length, units.length);
     for (int i = 0; i < s.length; i++) {
       Expect.equals(s.codeUnitAt(i), units.elementAt(i));
     }
 
     // for-in
     var res = [];
     for (int unit in units) {
       res.add(unit);
     }
     Expect.listEquals(expectedUnits, res);
 
     // .map
     Expect.listEquals(expectedUnits.map((x) => x.toRadixString(16)).toList(),
                       units.map((x) => x.toRadixString(16)).toList());
+
+    if (s == "") {
+      Expect.throws(() => units.first, (e) => e is StateError);
+      Expect.throws(() => units.last, (e) => e is StateError);
+      Expect.throws(() => units[0], (e) => e is RangeError);
+      Expect.throws(() => units[0] = 499, (e) => e is UnsupportedError);
+      Expect.listEquals([], units.getRange(0, 0));
+      Expect.equals(-1, units.indexOf(42));
+      Expect.equals(-1, units.lastIndexOf(499));
+    } else {
+      Expect.equals(s.codeUnitAt(0), units.first);
+      Expect.equals(s.codeUnitAt(s.length - 1), units.last);
+      Expect.equals(s.codeUnitAt(0), units[0]);
+      Expect.throws(() { units[0] = 499; }, (e) => e is UnsupportedError);
+      List<int> sub = units.getRange(1, units.length - 1);
+      Expect.listEquals(s.substring(1, s.length).codeUnits, sub);
+      Expect.equals(-1, units.indexOf(-1));
+      Expect.equals(0, units.indexOf(units[0]));
+      Expect.equals(-1, units.lastIndexOf(-1));
+      Expect.equals(units.length - 1, units.lastIndexOf(units[units.length - 1]));
+    }
+
+    Iterable reversed = units.reversed;
+    int i = units.length - 1;
+    for (int codeUnit in reversed) {
+      Expect.equals(units[i--], codeUnit);
+    }
   }
 
+  test("");
   test("abc");
   test("\x00\u0000\u{000000}");
   test("\u{ffff}\u{10000}\u{10ffff}");
   String string = new String.fromCharCodes(
       [0xdc00, 0xd800, 61, 0xd9ab, 0xd9ab, 0xddef, 0xddef, 62, 0xdc00, 0xd800]);
   test(string);
   string = "\x00\x7f\xff\u0100\ufeff\uffef\uffff"
            "\u{10000}\u{12345}\u{1d800}\u{1dc00}\u{1ffef}\u{1ffff}";
   test(string);
 
   // Reading each unit of a surrogate pair works.
   var r = "\u{10000}".codeUnits;
   var it = r.iterator;
   Expect.isTrue(it.moveNext());
   Expect.equals(0xD800, it.current);
   Expect.isTrue(it.moveNext());
   Expect.equals(0xDC00, it.current);
 }