On 13 January 2014 09:08, Fabio Zadrozny fabi...@gmail.com wrote:
Hi Python-dev.
I'm playing a bit on the concept on live-coding during a debug session and
one of the most annoying things is that although I can reload the code for a
function (using something close to xreload), it seems it's not possible to
change the code for the current frame (i.e.: I need to get out of the
function call and then back in to a call to the method from that frame to
see the changes).
I gave a look on the frameobject and it seems it would be possible to set
frame.f_code to another code object -- and set the line number to the start
of the new object, which would cover the most common situation, which would
be restarting the current frame -- provided the arguments remain the same
(which is close to what the java debugger in Eclipse does when it drops the
current frame -- on Python, provided I'm not in a try..except block I can do
even better setting the the frame.f_lineno, but without being able to change
the frame f_code it loses a lot of its usefulness).
So, I'd like to ask for feedback from people with more knowledge on whether
it'd be actually feasible to change the frame.f_code and possible
implications on doing that.
Huh, I would have sworn there was already an issue on the tracker
about that, but it appears not (Eric Snow has one about adding a
reference to the running function, but nothing about trying to switch
an executing frame: http://bugs.python.org/issue12857).
Anyway, your main problem isn't the reference to the code object from
the frame: it's the fact that the main eval loop has a reference to
that code object from a C level stack variable, and stores a bunch of
other state directly on the C stack.
I don't see anything *intrinsically* impossible about the idea, it
just wouldn't be easy, since you'd have to come up with a way of
dealing with that C level state that didn't slow down normal
operation.
Cheers,
Nick.
--
Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia
___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
