/// <summary>
/// Compares two class instances.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="comparer">The comparer.</param>
/// <param name="incomparable">
/// Whether objects are incomparable while no difference is found before both objects enter an infinite recursion, returns zero.
/// </param>
static int CompareObjects(object x, object y, PhpComparer comparer, out bool incomparable)
{
Debug.Assert(x != null && y != null);
incomparable = false;
// check for same instance
if (ReferenceEquals(x, y))
{
return(0);
}
// check for different types
var type_x = x.GetType().GetTypeInfo();
var type_y = y.GetType().GetTypeInfo();
if (type_x != type_y)
{
if (type_x.IsSubclassOf(type_y.AsType()))
{
return(-1);
}
if (type_y.IsSubclassOf(type_x.AsType()))
{
return(1);
}
incomparable = true;
return(1); // they really are incomparable
}
// check for different number of fields
int result = TypeMembersUtils.FieldsCount(x) - TypeMembersUtils.FieldsCount(y);
if (result != 0)
{
return(result);
}
throw new NotImplementedException();
}
static int CompareObjects(object x, object y, PhpComparer comparer, out bool incomparable, ref HashSet <object> visited)
{
Debug.Assert(x != null && y != null);
incomparable = false;
// check for same instance
if (ReferenceEquals(x, y))
{
return(0);
}
// check for different types
var type_x = x.GetType();
var type_y = y.GetType();
if (type_x != type_y)
{
if (type_x.IsSubclassOf(type_y))
{
return(-1);
}
if (type_y.IsSubclassOf(type_x))
{
return(1);
}
incomparable = true;
return(1); // they really are incomparable
}
// same type
var phpt = type_x.GetPhpTypeInfo();
// TODO: check PhpReference
// compare properties:
// the comparison operation stops and returns at the first unequal property found
//if (visited == null)
//{
// visited = new HashSet<object>();
//}
//if (visited.Add(x) == false && visited.Add(y) == false)
//{
// // both objects already visited, break the recursion
// return 0;
//}
// TODO: infinite recursion prevention
foreach (var p in phpt.GetDeclaredProperties())
{
if (p.IsStatic)
{
continue;
}
var val_x = p.GetValue(null, x);
var val_y = p.GetValue(null, y);
var result = comparer.Compare(val_x, val_y);
if (result != 0)
{
return(result);
}
}
// compare runtime properties:
var arr_x = phpt.GetRuntimeFields(x);
var arr_y = phpt.GetRuntimeFields(y);
var count_x = arr_x != null ? arr_x.Count : 0;
var count_y = arr_y != null ? arr_y.Count : 0;
if (count_x != 0)
{
if (count_y == 0)
{
return(count_x);
}
var enumerator = arr_x.GetFastEnumerator();
while (enumerator.MoveNext())
{
// TODO: if (!arr_y.TryGetValue(...)) ...
var result = comparer.Compare(enumerator.CurrentValue, arr_y[enumerator.CurrentKey]);
if (result != 0)
{
return(result);
}
}
}
return(count_x - count_y);
}
/// <summary>
/// Compares two class instances.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="comparer">The comparer.</param>
/// <param name="incomparable">
/// Whether objects are incomparable while no difference is found before both objects enter an infinite recursion, returns zero.
/// </param>
static int CompareObjects(object x, object y, PhpComparer comparer, out bool incomparable)
{
HashSet <object> visited = null;
return(CompareObjects(x, y, comparer, out incomparable, ref visited));
}