Re: [Jython-users] compiling Python to JVM bytecode

[Noel R. <no...@ya...>]

At 02:05 PM 3/4/02, you wrote:
>I'm interested in learning more about how jythonc works. I see that it 
>produces an intermediate file which is then compiled to bytecode with javac.
>
>A few questions come to mind:
>
>Did the creators consider using Java as an intermediate, rather than 
>generating bytecode directly (OK, Java source code is easier to produce, 
>but isn't it possible to compile non-Java directly to bytecode?)

The jython interpreter does generate bytecode directly and 
on-the-fly.  However, to capture the full dynamic range of jython behavior 
(things like module reloading, the exec statement, and the like), jython 
uses a custom ClassLoader in the interpreter.  Since jythonc is supposed to 
allow you to use jython in places where an actual .class or .jar file is 
required, and where a custom ClassLoader might violate security, jythonc 
creates actual Java source.  As a result, jythonc is a little stricter 
about Java subclassing, and may also have trouble with dynamic things like 
generating a base class at run-time.

>More generally: Is there any documentation available about how jythonc works?

<shameless plug>
The forthcoming _Java Essentials_ from O'Reilly has a chapter about 
jythonc, mostly from a user perspective, but also containing information 
about how it works and the generated Java source.
</shameless plug>

Hope this helps,

Noel Rappin


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