private static IntervalCollection <T> HighUnionOf <T>(Interval <T> a, Interval <T> b)
{
if (Interval.IsNullOrEmpty(a))
{
return(new IntervalCollection <T>(b));
}
if (Interval.IsNullOrEmpty(b))
{
return(new IntervalCollection <T>(a));
}
var lowestBound = Bound.Min(a.LowerBound, b.LowerBound);
var upmostValue = Bound.Max(a.UpperBound, b.UpperBound);
var lowerBound = default(Bound <T>);
var upperBound = default(Bound <T>);
// a
//-------------
// b
// ---------
if (object.Equals(lowestBound, a.LowerBound) &&
object.Equals(upmostValue, a.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Max(a.LowerBound.Direction, b.LowerBound.Direction)
: a.LowerBound.Direction
, a.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Max(a.UpperBound.Direction, b.UpperBound.Direction)
: a.UpperBound.Direction
, a.UpperBound.Value);
}
// a
// ---------
// b
//-------------
else if (object.Equals(lowestBound, b.LowerBound) &&
object.Equals(upmostValue, b.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Max(a.LowerBound.Direction, b.LowerBound.Direction)
: b.LowerBound.Direction
, b.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Max(a.UpperBound.Direction, b.UpperBound.Direction)
: b.UpperBound.Direction
, b.UpperBound.Value);
}
// a
//---------
// b
// -------------
else if (object.Equals(lowestBound, a.LowerBound) &&
object.Equals(upmostValue, b.UpperBound) &&
a.UpperBound.UnionCompareTo(b.LowerBound) >= 0)
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Max(a.LowerBound.Direction, b.LowerBound.Direction)
: a.LowerBound.Direction
, a.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Max(a.UpperBound.Direction, b.UpperBound.Direction)
: b.UpperBound.Direction
, b.UpperBound.Value);
}
// a
// -------------
// b
//---------
else if (object.Equals(lowestBound, b.LowerBound) &&
object.Equals(upmostValue, a.UpperBound) &&
b.UpperBound.UnionCompareTo(a.LowerBound) >= 0)
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Max(a.LowerBound.Direction, b.LowerBound.Direction)
: b.LowerBound.Direction
, b.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Max(a.UpperBound.Direction, b.UpperBound.Direction)
: a.UpperBound.Direction
, a.UpperBound.Value);
}
else
{
return(new IntervalCollection <T>(a, b));
}
Interval <T> result;
return(TryParse(lowerBound, upperBound, out result)
? new IntervalCollection <T>(result)
: new IntervalCollection <T>(a, b));
}
/// <summary>
/// Determines the intersection of two intervals.
/// </summary>
/// <typeparam name="T">The value type of the intervals.</typeparam>
/// <param name="a">The first interval.</param>
/// <param name="b">The second interval.</param>
/// <returns>An <see cref="Interval<T>"/> that contains all elements of <paramref name="a"/>
/// that also belong to <paramref name="b"/> (or equivalently, all elements of <paramref name="b"/>
/// that also belong to <paramref name="a"/>), but no other elements.</returns>
/// <seealso href="http://en.wikipedia.org/wiki/Intersection_(set_theory)">Intersection (set theory)</seealso>
private static Interval <T> IntersectionOf <T>(Interval <T> a, Interval <T> b)
{
if (Interval.IsNullOrEmpty(a))
{
return(a);
}
if (Interval.IsNullOrEmpty(b))
{
return(b);
}
var lowestBound = Bound.Min(a.LowerBound, b.LowerBound);
var upmostValue = Bound.Max(a.UpperBound, b.UpperBound);
var lowerBound = default(Bound <T>);
var upperBound = default(Bound <T>);
// a
//-------------
// b
// ---------
if (object.Equals(lowestBound, a.LowerBound) &&
object.Equals(upmostValue, a.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Min(a.LowerBound.Direction, b.LowerBound.Direction)
: b.LowerBound.Direction
, b.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Min(a.UpperBound.Direction, b.UpperBound.Direction)
: b.UpperBound.Direction
, b.UpperBound.Value);
}
// a
// ---------
// b
//-------------
else if (object.Equals(lowestBound, b.LowerBound) &&
object.Equals(upmostValue, b.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Min(a.LowerBound.Direction, b.LowerBound.Direction)
: a.LowerBound.Direction
, a.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Min(a.UpperBound.Direction, b.UpperBound.Direction)
: a.UpperBound.Direction
, a.UpperBound.Value);
}
// a
//---------
// b
// -------------
else if (object.Equals(lowestBound, a.LowerBound) &&
object.Equals(upmostValue, b.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Min(a.LowerBound.Direction, b.LowerBound.Direction)
: b.LowerBound.Direction
, b.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Min(a.UpperBound.Direction, b.UpperBound.Direction)
: a.UpperBound.Direction
, a.UpperBound.Value);
}
// a
// -------------
// b
//---------
else if (object.Equals(lowestBound, b.LowerBound) &&
object.Equals(upmostValue, a.UpperBound))
{
lowerBound = new Bound <T>(BoundType.Lower
, object.Equals(a.LowerBound.Value, b.LowerBound.Value)
? Bound.Min(a.LowerBound.Direction, b.LowerBound.Direction)
: a.LowerBound.Direction
, a.LowerBound.Value);
upperBound = new Bound <T>(BoundType.Upper
, object.Equals(a.UpperBound.Value, b.UpperBound.Value)
? Bound.Min(a.UpperBound.Direction, b.UpperBound.Direction)
: b.UpperBound.Direction
, b.UpperBound.Value);
}
else
{
return(Interval.Empty <T>());
}
Interval <T> result;
return(TryParse(lowerBound, upperBound, out result)
? result
: Interval.Empty <T>());
}
/// <summary>
/// Determines whether two intervals intersect each other.
/// </summary>
/// <typeparam name="T">The value type of the intervals.</typeparam>
/// <param name="a">The first interval.</param>
/// <param name="b">The second interval.</param>
/// <returns><c>true</c> if the <see cref="Interval<T>"/> <paramref name="a"/> intersects the interval <paramref name="b"/>; otherwise, <c>false</c>.</returns>
public static bool Intersect <T>(Interval <T> a, Interval <T> b)
{
return(!IsNullOrEmpty(IntersectionOf(a, b)));
}
/// <summary>
/// Determines the intersection of two intervals.
/// </summary>
/// <typeparam name="T">The value type of the intervals.</typeparam>
/// <param name="a">The first interval.</param>
/// <param name="b">The second interval.</param>
/// <param name="intersection">When this method returns, contains the <see cref="Interval<T>"/>
/// that contains all elements of <paramref name="a"/> that also belong to <paramref name="b"/>;
/// otherwise, an empty interval.</param>
/// <returns><b>true</b> if the intersection is not empty; otherwise, <b>false</b>.</returns>
public static bool TryIntersectionOf <T>(Interval <T> a, Interval <T> b, out Interval <T> intersection)
{
intersection = IntersectionOf(a, b);
return(!IsNullOrEmpty(intersection));
}
/// <summary>
/// Indicates whether the specified <see cref="Interval<T>"/> object is <c>null</c> or an <see cref="P:Interval´1.Empty"/> interval.
/// </summary>
/// <typeparam name="T">The value type of the interval.</typeparam>
/// <param name="value">An <see cref="Interval<T>"/> reference.</param>
/// <returns>
/// <c>true</c> if the <paramref name="value"/> parameter is <c>null</c> or an emty interval; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullOrEmpty <T>(Interval <T> value)
{
return(object.Equals(value, default(Interval <T>)) || value.IsEmpty);
}