optimization with the "compiler" module

[Andrew Dalke]

Philip Swartzleonard:
>In this case, wouldn't 3+7.0+x be a Typeerror or something? Int doesn't
>know how to add with a Strange, and Strange dosen't have an upgrading
>function...

Yeah, it would.  First though, 3+7.0 is a float.  To get the behaviour
I mentioned, add

    __radd__ = __add__

to the class definition.

> or do we assume addition is always commutitive and try '3+x+
>7.0' (effectively), therefore breaking the optimization mentioned by the
>other... =)

Python nor most other languages can assume addition of unknown types
is communitive.  After all, "a"+"b"+"c" != "a"+"c"+"b".

                    Andrew