Language/Statements/Switch/execution_case_t01.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.

/// @assertion Execution of a case clause case ek: sk of a switch statement
/// switch (e) {
///   label11 … label1j1 case e1: s1
/// …
///   labeln1 ..labelnjn case en: sn
///   label(n+1)1 ..label(n+1)jn default: sn+1
/// }
/// proceeds as follows:
/// The expression ek == id  is evaluated to an object o which is then subjected
/// to boolean conversion yielding a value v. If v is not true, the following
/// case, case ek+1: sk+1 is executed if it exists. If case ek+1: sk+1 does not
/// exist, then the default clause is executed by executing sn+1. If v is true,
/// let h be the smallest integer such that h >= k and sh is non-empty. If no
/// such h exists, let h = n + 1. The sequence of statements sh is then executed.
/// If execution reaches the point after sh then a runtime error occurs, unless
/// h = n + 1.
/// @description Checks that the cases are tested in the specified order, top to
/// bottom and if there're no statements in the matching case, then Dart
/// continues looking for statements to execute down from there. Some case
/// expressions are equal to each other.
/// @author rodionov
/// @reviewer iefremov

import '../../../Utils/expect.dart';

test(value) {
  var result;

  switch (value) {
    case 3:
      return 1;
    case 1:
      return 2;
    case 2:
      return 3;
    case 1:
      return 4;
    case 1:
      return 5;
    case 2:
      return 6;
    case 4:
    case 5:
    case 6:
      return 7;
    default:
      return -1;
  }
  return result;
}

main() {
  Expect.equals(2, test(1));
  Expect.equals(3, test(2));
  Expect.equals(1, test(3));
  Expect.equals(7, test(4));
  Expect.equals(7, test(5));
  Expect.equals(7, test(6));
  Expect.equals(-1, test(7));
}