Re: [Jython-dev] Metaclasses, _doget, and ExtensionClasses

[Phillip J. E. <pj...@te...>]

At 03:42 AM 7/15/01 +0200, Samuele Pedroni wrote:

>So after the trouble of  a few posts and of making me propose a bad and not
>working hack, you came out
>with some actual code <wink>.

I could've proposed code to start with, but as you can see, my Java isn't 
as good as my Python.  :)

Here's a version of your patch that works with my minimal ExtensionClass 
emulation:

? org/python/util/PyMetaClass.java
Index: org/python/core/Py.java
===================================================================
RCS file: /cvsroot/jython/jython/org/python/core/Py.java,v
retrieving revision 2.46
diff -u -r2.46 Py.java
--- org/python/core/Py.java     2001/07/03 20:20:27     2.46
+++ org/python/core/Py.java     2001/07/15 14:18:27
@@ -1406,6 +1406,10 @@
      }


+    private static Class[] pyClassCtrSignature =
+        {String.class,PyTuple.class,PyObject.class,Class.class};
+
+
      public static PyObject makeClass(String name, PyObject[] bases,
                                       PyCode code, PyObject doc,
                                       Class proxyClass,PyObject[] 
closure_cells)
@@ -1419,6 +1423,14 @@
              dict.__setitem__("__doc__", doc);

          for (int i=0; i<bases.length; i++) {
+            if (bases[i] instanceof org.python.util.PyMetaClass) {
+                try {
+                    return 
(PyObject)bases[i].getClass().getConstructor(pyClass CtrSignature).newInstance(
+                        new Object[] { name, new PyTuple(bases), dict, 
proxyClass });
+                } catch (Exception e) {
+                    throw Py.TypeError("meta-class fails to supply proper 
ctr:"+bases[i].safeRepr());
+                }
+            }
              if (!(bases[i] instanceof PyClass)) {
                  PyObject c = bases[i].__class__;
                  // Only try the meta-class trick on __class__'s that are

It's the same as yours, except that it goes before the PyClass check, so 
that an object that "extends PyClass implements PyMetaClass" will be 
treated as a metaclass.


>plus an empty org.python.util.PyMetaClass interface
>could make into the code, no problem with that.

Thanks!  This will be a big help for my project, as now I'll be able to use 
ComputedAttributes in TransWarp without having to worry about there being 
no way to do them in Jython.