public bool Intersection(RangeElement other, out RangeElement intersection)
{
intersection = null;
if (other == null)
{
return(false);
}
// before
if (Begin.Begin.CompareTo(other.End.End) > 0)
{
return(false);
}
// after
if (End.End.CompareTo(other.Begin.Begin) < 0)
{
return(false);
}
string begin = (Begin.Begin.CompareTo(other.Begin.Begin) < 0) ? other.Begin.Begin : Begin.Begin;
string end = (End.End.CompareTo(other.End.End) > 0) ? other.End.End : End.End;
intersection = new RangeElement(begin, end);
return(true);
}
public bool Equals(RangeElement other)
{
if (ReferenceEquals(null, other))
{
return(false);
}
if (ReferenceEquals(this, other))
{
return(true);
}
return(Equals(other.Begin, Begin) && Equals(other.End, End));
}
public static IEnumerable <IRangeElement> RestrictTo(this IEnumerable <IRangeElement> requested, IEnumerable <IRangeElement> restriction)
{
int requestedCount = 0;
foreach (IRangeElement element in requested)
{
requestedCount++;
if (!restriction.Includes(element))
{
var range = element as RangeElement;
if (range != null)
{
RangeElement intersection = null;
restriction
.Where(x => x is RangeElement)
.Where(x => ((RangeElement)x).Intersection(range, out intersection))
.FirstOrDefault();
if (intersection != null)
{
yield return(intersection);
continue;
}
var includedResults = restriction
.Where(x => x is StartsWithElement)
.Where(range.Includes);
foreach (IRangeElement includedResult in includedResults)
{
yield return(includedResult);
}
}
continue;
}
yield return(element);
}
if (requestedCount == 0)
{
foreach (IRangeElement element in restriction)
{
yield return(element);
}
}
}
public bool Union(RangeElement other, out RangeElement combined)
{
combined = null;
if (other == null)
{
return(false);
}
if (Begin.Begin.CompareTo(other.Begin.Begin) <= 0 && End.End.CompareTo(other.Begin.Begin) >= 0)
{
combined = new RangeElement(Begin.Begin, (End.End.CompareTo(other.End.End) >= 0) ? End.End : other.End.End);
return(true);
}
if (End.End.CompareTo(other.End.End) >= 0 && Begin.Begin.CompareTo(other.End.End) <= 0)
{
combined = new RangeElement((Begin.Begin.CompareTo(other.Begin.Begin) <= 0) ? Begin.Begin : other.Begin.Begin, End.End);
return(true);
}
return(false);
}
