/** Interval objects are used readonly so share all with the
* same single value a==b up to some max size. Use an array as a perfect hash.
* Return shared object for 0..INTERVAL_POOL_MAX_VALUE or a new
* Interval object with a..a in it. On Java.g, 218623 IntervalSets
* have a..a (set with 1 element).
*/
public static Interval Create( int a, int b )
{
//return new Interval(a,b);
// cache just a..a
if ( a != b || a < 0 || a > INTERVAL_POOL_MAX_VALUE )
{
return new Interval( a, b );
}
if ( cache[a] == null )
{
cache[a] = new Interval( a, a );
}
return cache[a];
}
/** Return the interval with elements from this not in other;
* other must not be totally enclosed (properly contained)
* within this, which would result in two disjoint intervals
* instead of the single one returned by this method.
*/
public virtual Interval DifferenceNotProperlyContained( Interval other )
{
Interval diff = null;
// other.a to left of this.a (or same)
if ( other.StartsBeforeNonDisjoint( this ) )
{
diff = Interval.Create( Math.Max( this.a, other.b + 1 ),
this.b );
}
// other.a to right of this.a
else if ( other.StartsAfterNonDisjoint( this ) )
{
diff = Interval.Create( this.a, other.a - 1 );
}
return diff;
}
/** Are two intervals adjacent such as 0..41 and 42..42? */
public virtual bool Adjacent( Interval other )
{
return this.a == other.b + 1 || this.b == other.a - 1;
}
/** Return the interval computed from combining this and other */
public virtual Interval Union( Interval other )
{
return Interval.Create( Math.Min( a, other.a ), Math.Max( b, other.b ) );
}
/** Does this start after other? NonDisjoint */
public virtual bool StartsAfterNonDisjoint( Interval other )
{
return this.a > other.a && this.a <= other.b; // this.b>=other.b implied
}
/** Does this start at or before other? Nondisjoint */
public virtual bool StartsBeforeNonDisjoint( Interval other )
{
return this.a <= other.a && this.b >= other.a;
}
/** Does this.a start after other.b? May or may not be disjoint */
public virtual bool StartsAfter( Interval other )
{
return this.a > other.a;
}
/** Does this start completely after other? Disjoint */
public virtual bool StartsAfterDisjoint( Interval other )
{
return this.a > other.b;
}
public virtual bool ProperlyContains( Interval other )
{
return other.a >= this.a && other.b <= this.b;
}
/** Are both ranges disjoint? I.e., no overlap? */
public virtual bool Disjoint( Interval other )
{
return StartsBeforeDisjoint( other ) || StartsAfterDisjoint( other );
}
/** Return the interval computed from combining this and other */
public Interval Union( Interval other )
{
return Interval.FromBounds( Math.Min( a, other.a ), Math.Max( b, other.b ) );
}
/** Does this start completely before other? Disjoint */
public bool StartsBeforeDisjoint( Interval other )
{
return this.a < other.a && this.b < other.a;
}
public bool Equals(Interval other)
{
return this.a == other.a && this.b == other.b;
}
