[Numpy-discussion] PEP updated

[Travis Oliphant]

I've updated the PEP to conform to what I think is the best hybrid 
solution propsed and that is to implement a tree of PythonTypes in C 
whose leaves are (to the Python user) new rank-0 arrays.   This is
more work to implement (but I don't think a great deal of work see 
below), and I think it will lead to the best results under our current 
constraints.

Internally, the PyArray_Type will still deal with rank-0 arrays (in fact 
the new Python scalars will be converted to them internally rather than 
special-case a bunch of code).

I don't think we should try to solve the general number-hierchy in 
Python at this time.  We will implement the array-number hierarchy 
only.    If this leads to others getting interested in the general 
problem, then that may come, but now we have to focus on our objective 
of getting the arrayobject accepted into Python.

Note that these new rank-0 Python scalars will be simple, have the same 
methods and attributes as Python arrays (likely-implemented once in the 
GenericArrType by converting the object to a rank-0 array).
Also, they will inherit (multiple-inheritance is possible in C) from the 
appropriate Python Type where an exact-match is available.

-Travis