--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pydershell/pydershell.py	Sun Sep 06 11:12:35 2009 -0700
@@ -0,0 +1,87 @@
+import sys
+import time
+import threading
+import traceback
+import pydermonkey
+
+rt = pydermonkey.Runtime()
+cx = rt.new_context()
+globalobj = cx.new_object()
+cx.init_standard_classes(globalobj)
+
+def foo(cx, this, args):
+    return cx.call_function(this, args[0], ())
+
+cx.define_property(globalobj,
+                   'foo',
+                   cx.new_function(foo, 'foo'))
+
+def jsprint(cx, this, args):
+    if len(args) > 0:
+        print args[0]
+
+cx.define_property(globalobj,
+                   'print',
+                   cx.new_function(jsprint, 'print'))
+
+def opcb(cx):
+    # Don't do anything; if a keyboard interrupt was triggered,
+    # it'll get raised here automatically.
+    pass
+
+cx.set_operation_callback(opcb)
+
+class State(object):
+    def __init__(self):
+        self.curr_exc = None
+        self.curr_tb = None
+        self.curr_js_stack = None
+
+state = State()
+
+def throwhook(cx):
+    curr_exc = cx.get_pending_exception()
+    if state.curr_exc != curr_exc:
+        state.curr_exc = curr_exc
+        state.py_stack = traceback.extract_stack()
+        state.js_stack = cx.get_stack()
+
+cx.set_throw_hook(throwhook)
+
+def watchdog():
+    while 1:
+        time.sleep(0.25)
+        cx.trigger_operation_callback()
+
+thread = threading.Thread(target=watchdog)
+thread.setDaemon(True)
+thread.start()
+
+filename = 'test.js'
+
+def make_stack(js_stack):
+    lines = []
+    while js_stack:
+        if js_stack['script']:
+            script = js_stack['script']
+            thing = dict(filename = script.filename,
+                         lineno = js_stack['lineno'],
+                         name = '<module>')
+        elif js_stack['function'] and not js_stack['function'].is_python:
+            func = js_stack['function']
+            thing = dict(filename = func.filename,
+                         lineno = js_stack['lineno'],
+                         name = func.name)
+        else:
+            thing = None
+        if thing:
+            lines.insert(0, "  File \"%(filename)s\", line %(lineno)d, in %(name)s" % thing)
+        js_stack = js_stack['caller']
+    lines.insert(0, "Traceback (most recent call last):")
+    return '\n'.join(lines)
+
+try:
+    cx.evaluate_script(globalobj, open(filename).read(), filename, 1)
+except pydermonkey.error, e:
+    print make_stack(state.js_stack)
+    print e.args[1]

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pydershell/test.js	Sun Sep 06 11:12:35 2009 -0700
@@ -0,0 +1,13 @@
+print('hello there dood');
+
+function blah() {
+  print('hi');
+  try {
+    throw new Error('baffs');
+  } catch (e) {
+    print('exception is ' + e);
+    throw e;
+  }
+}
+
+foo(blah);