Specify the position of a boundary within some coordinates.

Arguments:

• position - The default integer position
• left - The start (left) position of the boundary
• right - The end (right) position of the boundary

This allows dealing with a position like ((1.4)..100). This indicates that the start of the sequence is somewhere between 1 and 4. Since this is a start coordinate, it should acts like it is at position 1 (or in Python counting, 0).

 >>> p = WithinPosition(10, 10, 13)
 >>> p
 WithinPosition(10, left=10, right=13)
 >>> print(p)
 (10.13)
 >>> int(p)
 10

Basic integer comparisons and operations should work as though this were a plain integer:

 >>> p == 10
 True
 >>> p in [9, 10, 11]
 True
 >>> p < 11
 True
 >>> p + 10
 20

 >>> isinstance(p, WithinPosition)
 True
 >>> isinstance(p, AbstractPosition)
 True
 >>> isinstance(p, int)
 True

Note this also applies for comparison to other position objects, where again the integer behaviour is used:

 >>> p == 10
 True
 >>> p == ExactPosition(10)
 True
 >>> p == BeforePosition(10)
 True
 >>> p == AfterPosition(10)
 True

If this were an end point, you would want the position to be 13:

 >>> p2 = WithinPosition(13, 10, 13)
 >>> p2
 WithinPosition(13, left=10, right=13)
 >>> print(p2)
 (10.13)
 >>> int(p2)
 13
 >>> p2 == 13
 True
 >>> p2 == ExactPosition(13)
 True

The old legacy properties of position and extension give the starting/lower/left position as an integer, and the distance to the ending/higher/right position as an integer. Note that the position object will act like either the left or the right end-point depending on how it was created:

 >>> p.position == p2.position == 10
 True
 >>> p.extension == p2.extension == 3
 True
 >>> int(p) == int(p2)
 False
 >>> p == 10
 True
 >>> p2 == 13
 True