# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1256599408 -3600
# Node ID 837ba944f563fe45776d0b52458cb9584a0168e9
# Parent  ed407c965ea509dd8f12d01cb38623b3f9d482be
Added tests for attribute deletion, currently disallowed.
Added notes about attribute usage optimisation effects.

diff -r ed407c965ea5 -r 837ba944f563 docs/optimisations.txt
--- a/docs/optimisations.txt	Mon Oct 26 01:03:38 2009 +0100
+++ b/docs/optimisations.txt	Tue Oct 27 00:23:28 2009 +0100
@@ -224,7 +224,16 @@
 the earliest opportunity and then specialise the attribute accesses, perhaps
 also invocations, in the generated code. AttributeError occurrences would need
 to be considered, however, potentially disqualifying certain attributes from
-any optimisations, and control flow would also need to be considered.
+any optimisations, and control flow would also need to be considered. The
+result would resemble the following:
+
+    def f(x, y):
+        if not isinstance(x, C):
+            raise TypeError
+        x.method(y)
+        if x.something:
+            ...
+        return x.attr
 
 Implemented Optimisation Types
 ==============================
diff -r ed407c965ea5 -r 837ba944f563 micropython/ast.py
--- a/micropython/ast.py	Mon Oct 26 01:03:38 2009 +0100
+++ b/micropython/ast.py	Tue Oct 27 00:23:28 2009 +0100
@@ -501,6 +501,9 @@
 
         "Assign the assignment expression to the recipient 'node'."
 
+        if node.flags == "OP_DELETE":
+            raise TranslationNotImplementedError(self.module.full_name(), node, "AssName(OP_DELETE)")
+
         self._visitName(node, self.name_store_instructions)
         self.set_source()
 
diff -r ed407c965ea5 -r 837ba944f563 micropython/inspect.py
--- a/micropython/inspect.py	Mon Oct 26 01:03:38 2009 +0100
+++ b/micropython/inspect.py	Tue Oct 27 00:23:28 2009 +0100
@@ -455,6 +455,9 @@
         return None
 
     def visitAssName(self, node):
+        if node.flags == "OP_DELETE":
+            raise InspectError(self.full_name(), node, "Deletion of attribute %r is not supported." % node.name)
+
         self.store(node.name, self.expr)
         self.use_name(node.name)
         return None
diff -r ed407c965ea5 -r 837ba944f563 tests/failure/delete_name.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/failure/delete_name.py	Tue Oct 27 00:23:28 2009 +0100
@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+
+a = 123
+del a
+
+# vim: tabstop=4 expandtab shiftwidth=4