[Jython-dev] reloading...

[Samuele P. <pe...@in...>]

Hi.

I'm about to start working on some experimental support for reloading of
java classes.
The interface will be somehow different - as already discussed long time
ago - to that for python modules.
Now the required primitives are in place in the codebase, and the class name
clash bug is fixed.

    For the moment I imagine three levels/ways of support for reload
These are illustrated in the form of some examples of usage (the interface
is clearly not definitive):
0)
    import reload
    reload.createLoadSet("XLS",['d:/exp','d:/exp2'])

    import XLS.com.xyz.utils.BlobReader
    from XLS.com.xyz.utils import Blob

    print XLS.com.xyz.utils.BlobWriter.getVersion()

    reload(XLS)

   # Blob still refers to the old/same version

    print XLS.com.xyz.utils.BlobWriter.getVersion() # refers to new version
    # XLS.com.xyz.utils.BlobReader
1)
    import reload
    xls =
reload.createLoadSet('<anononymous>',['d:/exp','d:/exp2'],topExport=['com.xy
z'])
    # works only if com.xyz is not an existing package under the hierarchy
    # controlled by the system package manager

    print com.xyz.utils.BlobWriter.getVersion() # this works without
prefixing with the load-set

    xls.reload()

   print com.xyz.utils.BlobWriter.getVersion() # new version
2) # same as 1, but should work for packages that are also under control of
the system package manager
    # with that is not meant that we have reloading from classpath or
sys.path
    # but that package content could be splitted between a fixed part coming
from classpath, sys.path
    # and a reloadable one coming from a separated set of directories

Clearly a possibility is to have all them together.
0) I feel is the "more pythonic" being a load set some kind of package that
can be reloaded as a whole.
It also the less confusing for the user.
1) This has the big advantage that the code for the development/test phase
and the final code contain the same imports.
  Can be a bit more confusing.
*)  Clearly the idea is that the reload.createLoadSet are idempotent. To
have the "same" call in many modules
  should report no error... Clearly at least one call should be issued
before trying to import things from
  the load-set.
2) Is more complicated to implement and can be very confusing. I do not know
wheter it's worth the effort.

I think 1+2 make sense.

Comments are welcome.

regards, Samuele Pedroni.