[Jython-users] Storing code objects

[Jim A. <ji...@tr...>]

Question:

How do I comvert a compiled code object to some kind of bytestream?
'Pickle' can't handle PyCode ("can't pickle ...PyTableCode object"), and
PyCode is not serializable. Am I missing something or is there no way to
do this easily?

Backround:

I am prototyping a program that uses Jython to allow users to design
forms by entering Jython expressions which are evaluated based on a
large set of XML data that is 'scoped' into the PythonInterpreter
beforehand. (Example: 'Customer.Name' or 'for p in Customer.Phones:
print p') We have built a GUI that displays the forms and allows entry
of the expressions, the 'definition' of the form is stored in XML along
with Fonts, justification, and other formatting info. After each
expression is evaluated the result is 'massaged' using various Java
routines to build a complete page.

The previous version used JavaScript (Rhino) but I'm trying to switch it
to Python to make it easier for the form designers.

I'm having a problem, though, with the speed: when interpreting
expressions Jython is half the speed of Rhino: this is critical for this
app.

I timed the compile compared the the 'eval' and found the compile takes
90% of the time:

 PyCode code = __builtin__.compile(evalLine, "<string>", "eval");  //
90%

 PyObject result = python.eval( (PyCode)code );                    //
10% !!

If I could store the compiled 'code objects' within the forms somehow I
think I could increase the speed of the forms 10x, but I can't figure
out a way to get some kind of 'bytestream' of the code object.

-- 
                                 __o
Jim Adrig                      _ \<,_
ji...@tr...          ' `/ ' `
                  ___________ `-'  `-'

Flon's Law:
        There is not now, and never will be, a language in
        which it is the least bit difficult to write bad programs.