Re: [Jython-dev] *loading: trying to summarize: clarifications (ii)

[<bc...@wo...>]

[Samuele]

>[Finn]
>> >> >sys.path (py) > java pkgs > sys.path (java) maybe is better ?
>> >> >if P is py pkg, import P will load the py pkg P independently of
>> >classpath...
>> >> >One will be still able to access the shadowed java pkg through the py
>> >pkg.
>> >>
>> >> Yes, I think this would be better.
>> >
>> >Fine, but as I wrote in a succesive mail, JimH put this precedence in place
>> >to avoid possible performance penalties
>> >by lookup in "applets" case: ...
>> 
>> Jythonc already goes through great pains to detect which of the name
>> spaces imported is actually java packages. The list of packages is then
>> initialized in Py.initProperties. Could we define that this explicit
>> list of identified java packages should be searched before all the
>> others?
>
>Yes but the performance problem is with sys.path(py) not the java pkgs,
>for them we already collect static information in PackageManager
>also based on the list constructed by jythonc.
>
>What we need (my opinion): we need an analougous list for the py pkgs:
>so given a pkg name -in the import code- we can avoid to lookup for name x.y as
>a compiled py pkg/module when it is in fact a java pkg.
>We cannot just use the java pkg information because with the new order
>py pkg can hide them and we want import to deliver a py pkg if it's the case.

Right, I think I understand now. The list of module would then look
like:

  module_list = ['x', 'x.y']

and the code that look for java packages would then look like this:

  if module_list != None:
     if modName in module_list:
         # here modName is not a java package, so there
         # is no need to try an expensive forName(modName)
         # across the network.
         return null
  // do normal java package load here.

>This list can also be a real mapping py pkg -> java class.

You've lost me here. Are you saying that the module list should be like
this:

  { 'x'   : 'x.__init__', 
    'x.y' : 'x.y' }

?
 
>This would make thing clearer and enable some interesting but clean
>features. For example if your compiled code run not under a sec. mgr
>you can change the value of sys.path and load also code from there.

regards,
finn