internal static INodeComparer <TResult, TStep> CreateComparer <TResult, TKey, TStep>(Func <TResult, TKey> keySelector, IComparer <TKey> keyComparer, bool descending)
{
if (keyComparer != null)
{
return(new NormalComparer <TStep, TResult, TKey>(keySelector, keyComparer, descending));
}
var comparer = default(INodeComparer <TResult, TStep>);
switch (Type.GetTypeCode(typeof(TKey)))
{
case TypeCode.Byte:
case TypeCode.Decimal:
case TypeCode.Double:
case TypeCode.Int16:
case TypeCode.Int32:
case TypeCode.Int64:
case TypeCode.SByte:
case TypeCode.Single:
case TypeCode.UInt16:
case TypeCode.UInt32:
case TypeCode.UInt64:
comparer = new HeuristicComparer <TStep, TResult, TKey>(keySelector, descending);
break;
default:
comparer = new NormalComparer <TStep, TResult, TKey>(keySelector, null, descending);
break;
}
return(comparer);
}
internal HeuristicSearchOrderBy <TFactor, TStep> CreateOrderedEnumerable(Func <TFactor, double> keySelector, bool descending)
{
if (keySelector == null)
{
throw new ArgumentNullException(nameof(keySelector));
}
var comparer1 = _nodeComparer;
var comparer2 = new HeuristicComparer <TFactor, TStep>(keySelector, descending);
_nodeComparer = new CombinedComparer <TFactor, TStep>(comparer1, comparer2);
return(this);
}