Re: [Pydev-code] Fwd: Viewing ASTs in PyDev

[Ueli K. <uki...@hs...>]

Hi,

basically you need to write your own visitor class.
This is easily done extending VisitorBase. VisitorBase will traverse 
"automatically" all nodes you don't want to handle yourself.
Override the traverse-method and call "node.traverse(this)".

For the nodes you are interested in:
This class will traverse all nodes of the AST and use a "callback" 
method when traversing a node.
E.g. if it traverses a ClassDef Node it will call visitClassDef(ClassDef 
node).
So actually the visitor can construct your treeview-model, if you just 
override all the visit-Methods for AST nodes you require.
E.g. visitClassDef, visitFunctionDef, visitCall, etc. etc. ..

Note also that there are different AST nodes for "variables" and also 
for "control structures"...
you should be able to figure out what is what for by having a look at 
the AST Rewriter i wrote for PEPTIC (especiall visit-methods).
Have a look at 
http://pydev.cvs.sourceforge.net/pydev/org.python.pydev.refactoring/src/org/python/pydev/refactoring/ast/rewriter/RewriterVisitor.java?revision=1.2&view=markup

Cheers,
    Ueli

--

Neil wrote:
> Hi Fabio, I'm following along with the mailing list advice stated here:
> http://www.nabble.com/PyDev-Extension-Points-Quick-Fix-%28copied-from-pydev-forum%29-tf503666.html#a1365501
>
> where you advise extending from pydev_builder to walk the AST.
>
> However, I'm  new to Eclipse plugin programming so I wonder if you
> could be a bit more specific.
>
> Currently my plugin does something like:
>
> public class PyGoal extends PyDevBuilderVisitor {
> SourceModule sm = (SourceModule) getSourceModule(resource, document, nature);
> SimpleNode sn = sm.getAst();
> EasyASTIteratorVisitor vis = new EasyASTIteratorVisitor();
>         try{
>                 sn.accept(vis);
>         } catch(Exception e) {}
> }
> What I'd like to do is create a simplified syntax tree structure that
> just stores functions, variables, control structures, and calls.  I'd
> then do various specific things to that tree for my own plugin.
>
> Can you illustrate how I would visit a particular document's AST,
> putting the elements of interest in my own data structure? How do I
> tell the PyDevBuilderVisitor what document/resource I'm working with?
>
> thanks
> neil ernst
>
> On 4/25/07, Neil Ernst <ne...@cs...> wrote:
>   
>> I think it would look something like the JDT AST viewer plugin:
>> http://www.eclipse.org/articles/Article-JavaCodeManipulation_AST/index.html
>>
>> I think I should probably create a separate plugin project that calls
>> on PyDev to do the actual AST generation, then load that into my
>> plugin.
>>
>> thanks for the advice
>> neil
>>
>> On 4/25/07, Ueli Kistler <uki...@hs...> wrote:
>>     
>>> Hi,
>>>
>>> i would not recommend using JGraph as I did... it would make more sense
>>> to extend the current outline view or provide a new "outline"-like view
>>> (i think there can be only one "true" outline view actually because its
>>> bound to an editor implementation? Not sure about this..)
>>>
>>> This could of course be done in a separate project... it would require
>>> similiar dependencies from PyDev as PEPTIC.
>>>
>>> Cheers,
>>> Ueli
>>>
>>> --
>>>
>>>
>>>
>>>
>>>
>>> Fabio Zadrozny wrote:
>>>       
>>>>> My first challenge is to view the ASTs for the entire project (I'm
>>>>> looking at the Trac source code). I notice in your code you have a
>>>>> class for viewing the AST using JGraph.  Would you be able to point me
>>>>> to a way to have this done in PyDev? I've been exploring the Jython
>>>>> scripting elements of PyDev but I can't get your viewer to start that
>>>>> way.
>>>>>           
>>>> The viewer that uses JGraph is not bundled in the pydev distribution
>>>> and thus cannot be accessed with the scripting... If you have the
>>>> source code, you can change those files from the 'contrib' source
>>>> folder to the actual 'src' source folder so that they can be accessed
>>>> (and add the related jars as dependencies for the plugin... or maybe a
>>>> better idea would be creating another plugin to hold those things,
>>>> which you can use and extend with your own code).
>>>>
>>>> Also, I think I would need more info on what you actually want to
>>>> access to help you better...
>>>>
>>>> Cheers,
>>>>
>>>> Fabio
>>>>         
>>>       
>
>
>