# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1480203230 -3600
# Node ID 41e0c7358ddf6ec5371eb9e4089a45bfbe0940f0
# Parent  d35cdc51ff845ca8ee2240d67aed67396bd7adf0
Introduced the remaining store operations, raising TypeError for class-relative
assignments via instances, permitting object-relative accesses and signalling
inappropriate accessors at run-time.

diff -r d35cdc51ff84 -r 41e0c7358ddf templates/ops.c
--- a/templates/ops.c	Sat Nov 26 23:07:09 2016 +0100
+++ b/templates/ops.c	Sun Nov 27 00:33:50 2016 +0100
@@ -41,6 +41,14 @@
     return 1;
 }
 
+int __get_class_and_store(__ref obj, int pos, __attr value)
+{
+    /* Forbid class-relative assignments. */
+
+    __raise_type_error();
+    return 0;
+}
+
 /* Introspection. */
 
 int __is_instance(__ref obj)
@@ -124,6 +132,14 @@
 
 /* Attribute testing and storage operations. */
 
+int __check_and_store_via_class(__ref obj, int pos, int code, __attr value)
+{
+    /* Forbid class-relative assignments. */
+
+    __raise_type_error();
+    return 0;
+}
+
 int __check_and_store_via_object(__ref obj, int pos, int code, __attr value)
 {
     if (__HASATTR(obj, pos, code))
@@ -131,6 +147,10 @@
         __store_via_object(obj, pos, value);
         return 1;
     }
+
+    /* No suitable attribute. */
+
+    __raise_type_error();
     return 0;
 }
 
@@ -138,7 +158,11 @@
 {
     if (__check_and_store_via_object(obj, pos, code, value))
         return 1;
-    return __check_and_store_via_object(__get_class(obj), pos, code, value);
+
+    /* Forbid class-relative assignments. */
+
+    __raise_type_error();
+    return 0;
 }
 
 /* Context-related operations. */
diff -r d35cdc51ff84 -r 41e0c7358ddf templates/ops.h
--- a/templates/ops.h	Sat Nov 26 23:07:09 2016 +0100
+++ b/templates/ops.h	Sun Nov 27 00:33:50 2016 +0100
@@ -19,6 +19,7 @@
 /* Direct storage operations. */
 
 int __store_via_object(__ref obj, int pos, __attr value);
+int __get_class_and_store(__ref obj, int pos, __attr value);
 
 /* Introspection. */
 
@@ -43,6 +44,7 @@
 
 /* Attribute testing and storage operations. */
 
+int __check_and_store_via_class(__ref obj, int pos, int code, __attr value);
 int __check_and_store_via_object(__ref obj, int pos, int code, __attr value);
 int __check_and_store_via_any(__ref obj, int pos, int code, __attr value);
 
diff -r d35cdc51ff84 -r 41e0c7358ddf tests/attr_providers.py
--- a/tests/attr_providers.py	Sat Nov 26 23:07:09 2016 +0100
+++ b/tests/attr_providers.py	Sun Nov 27 00:33:50 2016 +0100
@@ -1,6 +1,7 @@
 class C:
     def __init__(self):
         self.a = 1
+        self.c = 3
 
     b = 2
 
@@ -22,11 +23,35 @@
 
     x.a = 7
     x.b = 8
+    return f(x)
+
+def h(x):
+    x.c
+    x.a = 4
+    x.b
+    return f(x)
 
 c = C()
 d = D()
 e = E()
 
-result1 = f(c) # (1, 2)
-result2 = f(d) # (3, 4)
-result3 = f(e) # (5, 6)
+print f(c)          # (1, 2)
+print f(d)          # (3, 4)
+print f(e)          # (5, 6)
+print f(E)          # (5, 6)
+
+try:
+    print g(c)      # should fail with an error caused by a test
+except TypeError:
+    print "g(c): c is not a suitable argument."
+
+print g(d)          # (7, 8)
+
+try:
+    print g(e)      # should fail with an error caused by a test
+except TypeError:
+    print "g(e): e is not a suitable argument."
+
+print g(E)          # (7, 8)
+
+print h(c)          # (4, 5)