/// <summary>
/// Reads a stringe from the input and advances the position by the number of characters read.
/// </summary>
/// <param name="length">The number of characters to read.</param>
/// <returns></returns>
public Stringe ReadStringe(int length)
{
int p = _pos;
_pos += length;
return(_stringe.Substringe(p, length));
}
/// <summary>
/// Returns a stringe whose endpoints are the specified stringes. The stringes must both belong to the same parent string.
/// </summary>
/// <param name="a">The first stringe.</param>
/// <param name="b">The second stringe.</param>
/// <returns></returns>
public static Stringe Range(Stringe a, Stringe b)
{
if (a == null)
{
throw new ArgumentNullException("a");
}
if (b == null)
{
throw new ArgumentNullException("b");
}
if (a._stref != b._stref)
{
throw new ArgumentException("The stringes do not belong to the same parent.");
}
if (a == b)
{
return(a);
}
if (a.IsSubstringeOf(b))
{
return(b);
}
if (b.IsSubstringeOf(a))
{
return(a);
}
// Right side of A intersects left side of B.
if (a._offset > b._offset && a._offset + a._length < b._offset + b._length)
{
return(a.Substringe(0, b._offset + b._length - a._offset));
}
// Left side of A intersects right side of B.
if (a._offset < b._offset + b._length && a._offset > b._offset)
{
return(b.Substringe(0, a._offset + a._length - b._offset));
}
// A is to the left of B.
if (a._offset + a._length <= b._offset)
{
return(a.Substringe(0, b._offset + b._length - a._offset));
}
// B is to the left of A.
if (b._offset + b._length <= a._offset)
{
return(b.Substringe(0, a._offset + a._length - b._offset));
}
return(null);
}
