[Python-3000] Abilities / Interfaces

[Terry Reedy]

"Kay Schluehr" <kay.schluehr at gmx.net> wrote in message 
news:456891DF.3060609 at gmx.net...
> Seems like we need more formal procedures for writing test than
> application code. This also solves the problem of expense of
> "verification" of typeclasses/concepts/abilities that need to be done
> just once for a class with a fixed interface and not each time when the
> class gets loaded from a module. The value of "test time" is increased
> to a higher status not unlike the role of "compile time" for static
> analysis in languages with default type systems. But maybe my head is
> just too far in the clouds when I'm thinking about the end of the
> static/dynamic language distinction using type reconstruction at "test
> time". Heavyweight frameworks naturally emerge also in Python but being
> latent. Reconstructing them from runtime information is a challenge for
> dynamically typed languages. A good enough approximation can be turned
> into a set of prescriptions. This is not much different from the way
> natural scientists frame reality according to Karl Poppers "logic of
> progress" ( hypothetical deductive method ). Regular enough data are
> used to form a hypothesis about the future behaviour of a system. This
> hypothesis is used to frame reality in a mathematical description - just
> like type systems. Making new experiments / measurents can falsify a yet
> established deductive system which leads to improved frames ( reframing
> ) and progressive understanding of systems properties. The role of tests
> in this approach is twofold: they check application code and keep
> information about the "true nature" of the programs behaviour using
> measurements which leads to automatical generation of a formal
> hypothesis of a systems behaviour that may become prescriptive i.e.
> forms a type system:

To me, run-on paragraphs (and the above seems to me to be at least three) 
have the same comprehension problems as run-on sentences ;-)

"In the clouds" indeed.  Maybe try again?

Terry Jan Reedy