Is a "real" C-Python possible?

[Kay Schluehr]

On Dec 12, 4:45 am, "Terry Reedy" <tjre... at udel.edu> wrote:
> "sturlamolden" <sturlamol... at yahoo.no> wrote in message
>
> news:6c73d2e1-1afb-469b-9132-671e03ffe741 at f3g2000hsg.googlegroups.com...
> | We could include optional static typing in
> | Python, and have an optional static optimizing native compiler for
> | selected portions of code.
>
> Python 3 will have optional 'type' annotations, where 'type' includes
> abstract base classes defined by the interface (methods).  So parameters
> could be annotated as a Number or Sequence, for instance, which is more
> useful often than any particular concrete type.  I strongly suspect that
> someone will use the annotations for compilation, which others will use
> them just for documentation and whatever else.
>
> tjr

On the danger of hurting some souls, I used to write a type feedback
system a few months ago, which automatically annotates source code
from runtime types. Each run of a program P yields a program TP which
is fully type annotated on covered branches. Since a possible compiler
might need more hints than just relying on the types of function
parameters I changed the syntax of Python slightly for displaying
local type annotations as well. For each Python program P exist
possibly infinitely many programs TP of an extended languages TPython
called "typed snapshots". Each of those snapshots might be translated
using translation machinery a la ShedSkin. From a software engineering
point of view early integration with CPython is required, which means
integration of native code on a per function base and possible
fallback to bytecode interpretation in order to preserve duck-typing.
In the literature such techniques are called "(Offline) Feedback
Driven Optimization", while "Online" techniques refer to JIT
compilation.

When TP is yielded from P the program TP might be used for other
purposes as well because each typed snaphsot suggests static
guarantees in a given type system. This might ease the productive
value of refactoring browsers or other tools used for languages with
type systems. I'm yet not sure about type systems for typed snapshots
but one might interpret them in an existing languages with type
systems.

Kay