Re: How to get function string name from i-th stack position?

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From	Ian Kelly <ian.g.kelly@gmail.com>
Date	2011-12-31 10:05 -0700
Subject	Re: How to get function string name from i-th stack position?
Newsgroups	comp.lang.python
Message-ID	<mailman.4263.1325351176.27778.python-list@python.org> (permalink)

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On Sat, Dec 31, 2011 at 4:41 AM, Lie Ryan <lie.1296@gmail.com> wrote:
> On 12/31/2011 08:48 AM, Ian Kelly wrote:
>>
>>
>> But they are two distinct function objects, and there is no way
>> programmatically to determine that they are the same function except
>> by comparing the bytecode (which won't work generally because of the
>> halting problem).
>
>
> Actually, it is often possible to determine that two functions are the same
> function, you simply need a to compare whether the function object lives in
> the same memory address. It is also possible to determine if two functions
> are different, if the function object are in different memory address than
> the function is different function.
>
> What is difficult to do due to the Halting problem is comparing whether two
> different functions are "equivalent" (and therefore interchangeable).

Yes, that is what I said.  You can determine whether two function
objects are the same, but not whether they are *mathematically* the
same function.

> I think the OP wants to find the former, not the latter. The former is
> trivial, the latter impossible.

Based on his subsequent clarification, I agree, although from his
original post it sounded like he was just trying to identify summing
functions in general.   However, finding the built-in sum function on
the stack is not trivial at all, perhaps not even possible.

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Thread

How to get function string name from i-th stack position? dmitrey <dmitrey15@gmail.com> - 2011-12-30 09:51 -0800
  Re: How to get function string name from i-th stack position? Tim Chase <python.list@tim.thechases.com> - 2011-12-30 12:35 -0600
    Re: How to get function string name from i-th stack position? dmitrey <dmitrey15@gmail.com> - 2011-12-30 10:43 -0800
      Re: How to get function string name from i-th stack position? Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-30 14:48 -0700
        Re: How to get function string name from i-th stack position? dmitrey <dmitrey15@gmail.com> - 2011-12-31 00:44 -0800
          Re: How to get function string name from i-th stack position? Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-31 10:13 -0700
      Re: How to get function string name from i-th stack position? Lie Ryan <lie.1296@gmail.com> - 2011-12-31 22:41 +1100
      Re: How to get function string name from i-th stack position? Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-31 10:05 -0700

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