[Python-3000] Discussions with no PEPs

[Phillip J. Eby]

At 06:06 PM 3/12/2007 -0700, Bill Janssen wrote:
>Phillip,
>
>I think there is a certain schizophrenia in Python between the older
>original procedural/functional orientation (itself somewhat split),
>and the newer-fangled (for Python) object style, between len(obj) and
>obj.len().

Where you see schizophrenia, I see a set of mostly very wise choices, actually.


>That's what makes it hard to evaluate the pros and cons
>between adding generic functions (as Lisp did, to support its own
>functional style), and adding interfaces (in whatever fashion) to
>support the object-oriented view of life.

And one of the benefits of Python is that it doesn't kowtow, Java-like to 
an exclusively "object-oriented view of life".  Life involves more than 
objects, thank goodness.  :)

Btw, I don't think the evaluation is difficult at all, and in any case it's 
a false dichotomy.  It's easy to implement interfaces and adaptation over 
generic functions, but much harder to do the reverse.  So if we have to 
start somewhere, we might as well start with the more powerful feature 
that's less prone to error and abuse.

In other words, if we must have interfaces, then let's steal more from 
Haskell (typeclasses and instances defined in terms of generic functions) 
and less from Java (ABCs and name-based abstract method collections).  :)