An instance-based (vector) Discussion on developing cross-version ActionScript applications

With the development of Flash, I believe that many teams or individuals have accumulated the essence of the corresponding period (general code blocks or some fixed patterns ).
Although some will be gradually eliminated with the development of Flash, most of us do not have time and energy to deal with these things.
Currently, the mainstream versions are as2.0 and as1.0, and as3.0 will soon become popular. Although the big trend is that the higher version gradually replaces the lower version, it is not a matter of time.
Flash is a special tool that can make things big or small, can be complex and simple, and the user population is also relatively complex. It is estimated that in the past 10 years, various versions have always been in full bloom, and each of them occupies a corresponding proportion in different fields.
The next obvious problem with this situation is compatibility, that is, whether we need to take into account all versions during development.
Here I use the above method to make an example of "vector and:

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Its concept is well known as "Object-Oriented ". Each vector is an object, the sum of vectors is also an object, and each vector is composed of several objects (points, lines, arrows ).
Applicable to flash player 7/flash player 8/later and as1.0/as2.0/later.