// Copyright (c) 2014, 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.

import "package:expect/expect.dart";

swap1(x,y,b) {
    if (b) {
        var t = x;
        x = y;
        y = t;
    }
    Expect.equals(2, x);
    Expect.equals(1, y);
}

swap2(x,y,z,w,b) {
    if (b) {
        var t = x;
        x = y;
        y = t;

        var q = z;
        z = w;
        w = q;
    }
    Expect.equals(2, x);
    Expect.equals(1, y);
    Expect.equals(4, z);
    Expect.equals(3, w);
}

swap3(x,y,z,b) {
    if (b) {
        var t = x;
        x = y;
        y = z;
        z = t;
    }
    Expect.equals(2, x);
    Expect.equals(3, y);
    Expect.equals(1, z);
}

swap4(x,y,z,b) {
    if (b) {
        var t = x;
        x = y;
        y = z; // swap cycle involves unused variable 'y'
        z = t;
    }
    Expect.equals(2, x);
    Expect.equals(1, z);
}

swap5(x,y,z,w,b,b2) {
    if (b) {
        var t = x;
        x = y;
        y = t;
    }
    if (b2) {
        var q = z;
        z = w;
        w = q;
    }
    Expect.equals(2, x);
    Expect.equals(1, y);
    Expect.equals(4, z);
    Expect.equals(3, w);
}

main() {
    swap1(1,2,true);
    swap1(2,1,false);

    swap2(1,2,3,4,true);
    swap2(2,1,4,3,false);

    swap3(1,2,3,true);
    swap3(2,3,1,false);

    swap4(1,2,3,true);
    swap4(2,3,1,false);

    swap5(1,2,3,4,true, true);
    swap5(1,2,4,3,true, false);
    swap5(2,1,3,4,false, true);
    swap5(2,1,4,3,false, false);
}