[Eric] Why does Rope sometimes not find a definition?

[Detlev Offenbach]

On Samstag, 1. November 2008, Ali Gholami Rudi wrote:
> Hi,
>
> On Sat, Nov 01, 2008 at 11:59:58AM +0000, OldGrantonian wrote:
> > Thanks for your very detailed explanation.
> >
> > BTW: Because I'm not a programmer, I need a good IDE to browse around
> > other people's code. I learn faster that way. I'm simultaneously trying
> > Komodo and Wing, and comparing identical searches in the same python
> > project. At the moment, I'm only interested in the "browsing"
> > functionality, such as finding definitions, finding occurrences, and so
> > on. Eric is vastly superior to the other two IDEs. (And Komodo would
> > charge £150 for the "Pro" version, which is the only version that has
> > object browsing.)
> >
> :-)
> :
> > >> On Fri, Oct 31, 2008 at 11:41 AM, Ali Gholami Rudi
> > >> <aliqrudi at gmail.com>
> >
> > wrote:
> >
> >     In order to find out the return value of get_main_widget(), rope
> > needs to know the object w holds.  Here, rope cannot infer the type of w;
> > the reason might be the source code of qt.qApp.topLevelWidget() is
> > unavailable (is this a c-extension module?)
> >
> >
> > Yes, topLevelWidget() is in C-code, which is in SIP files. So, it looks
> > as if the simple answer to my question is: Rope cannot find definitions
> > if (a) there is too much dynamic behavior, or (b) if the definitions are
> > not contained within a ".py" file. Is that true?
>
> With SOA (static object analysis) yes.  DOA (dynamic object analysis), on
> the other hand, works in dynamic situations.  For instance:
>
>   class C(object):
> 	pass
>
>   def create_c():
> 	return eval("C()")
>
>   c = create_c()
>
> DOA can find out the object c holds.  It actually collects the
> parameters and the return value of functions after they are called.  So
> it doesn't matter how the function is implemented.
>
> DOA should be enabled when executing modules and that makes them
> slow (to tell you the truth, because of it I rarely use it ;-) ).
>
> > --------------------------------------------------------
> >
> > I have some more questions. If you want me to split these questions into
> > separate posts, please let me know.
>
> However you prefer :-)
>
> > If I cannot find a definition because of behaviour that I have just
> > discussed, it would still be useful to be able to do a "manual" query
> > using "Find Occurrences". It seems that "Find Occurrences" only works
> > within Python files. So I need to use an external text-search tool to
> > find some occurrences of "get_main_widget" (see above), because this
> > occurs in SIP files as well as PY files.
> >
> > Maybe "Find Occurrences" could be based on a user-configurable option:
> > "Do you want to search in non-Python files?"
>
> Currently rope uses only its object data for matching names.  But other
> approaches are possible, too:
>
> * guessing the type based on attributes (see "taking a look at pysmell"
>   thread in rope-dev)
> * guessing the type based on the name itself (unsure option of rename
>   refactoring is an example of this)
>
> These approaches work good when there aren't many similar names in a
> project.
>
> Support for searching C files (or other textual files) can be easily
> added (if someone volunteers ;-) ).
>
> > If I use "Find Occurrences" to search for get_main_widget, there are 11
> > occurrences. (This agrees with my external text-search tool.)
> >
> > However, if I use "Find Occurrences" to search for get_main_widget from
> > within the file where it is defined, I get the message: "No occurrences
> > found."
>
> Find occurrences searches all of the files in a project.  So searching
> for a built-in variable or a name in a file outside the project should
> find all of the occurrences in the current project.  If it doesn't, it
> is probably a bug...
>
> > I have never succeeded in getting "Find Implementations" to work. I
> > sometimes get the message: "Rope error: Not a method!", and sometimes:
> > "Rope error: String out of range.", and sometimes: "Rope error: Not a
> > resolvable Python identifier selected.", and sometimes: "Rope error:
> > Cannot resolve the identifier." (For a specific definition, the message
> > is always the same.)
> >
> > Here is what I do:
> >
> > Highlight the name of the method in the following example:
> >
> > def get_main_widget():
> >
> > So I would highlight "get_main_widget"
> >
> > Then Refactoring > Query > Find Implementations
>
> Find implementations searches for the implementations of a method of a
> class.  For instance:
>
>   class A(object):
> 	def f(self):
> 		pass
>
>   class B(A):
>   	def f(self):
> 		pass
>
> Performing find implementations on A.f() would find B.f().
>
> > Before using any of the Rope searches, I need to highlight text. If the
> > file was never edited, this highlighting causes a random message to "save
> > or discard changes" before performing the search.
> >
> > I say "random" because the message occurs before at least 50% of the
> > searches, but I cannot figure out in advance when the message will appear
> > and when it will not appear.
>
> Seems to be eric-related, Detlev?

I would need step by step instructions on how to reproduce it.

Regards,
Detlev
-- 
Detlev Offenbach
detlev at die-offenbachs.de