[Python-Dev] Catching "return" and "return expr" at compile time

[Skip Montanaro]

    Mark> On my third hand, I would _really_ like to see this in a lint tool
    Mark> rather than in the core.  I realize there is no such tool at the
    Mark> moment, but IMO is where we should be heading.  Skip's return
    Mark> statement warnings are fine and a nice addition, but in my
    Mark> experience account for a trivial number of my errors.  Stuff like
    Mark> warning about a variable name used only once, for example, will
    Mark> probably never get into core Python but in my opinion is far more
    Mark> valuable.  So adding this "-w" switch is fine, but still doesnt
    Mark> give us the framework we need to actually create a truly useful
    Mark> package of warnings for the Python developer.

I'm not sure the stuff I wrote belongs in the core either, certainly not in
C code.  As I mentioned when I posted it though, I wasn't sure where a
PyLint type program already existed that I could simply graft onto.  I've
fiddled around enough with the compile.c code in the past couple of years
that I understand it fairly well already.

I do have some Python code that does peephole optimization on Python
bytecode.  I could have put it in there (it already divides functions into
basic blocks), but again, not many people have it laying about to play with.

Can we start/settle on a Python-based source code framework for this sort of
thing?  Ideally, I'd like to see a framework that brings the parser module's
output up to a level where mere mortals like me can reason about Python
code.

Skip