Add oldstyle-instance len, getitem, setitem

src/runtime/classobj.cpp

@@ -207,6 +207,9 @@ Box* instanceNonzero(Box* _inst) {
 
     Box* nonzero_func = _instanceGetattribute(inst, boxStrConstant("__nonzero__"), false);
 
+    if (nonzero_func == NULL)
+        nonzero_func = _instanceGetattribute(inst, boxStrConstant("__len__"), false);
+
     if (nonzero_func) {
         return runtimeCall(nonzero_func, ArgPassSpec(0), NULL, NULL, NULL, NULL, NULL);
     } else {
@@ -214,6 +217,30 @@ Box* instanceNonzero(Box* _inst) {
     }
 }
 
+Box* instanceLen(Box* _inst) {
+    RELEASE_ASSERT(_inst->cls == instance_cls, "");
+    BoxedInstance* inst = static_cast<BoxedInstance*>(_inst);
+
+    Box* len_func = _instanceGetattribute(inst, boxStrConstant("__len__"), true);
+    return runtimeCall(len_func, ArgPassSpec(0), NULL, NULL, NULL, NULL, NULL);
+}
+
+Box* instanceGetitem(Box* _inst, Box* key) {
+    RELEASE_ASSERT(_inst->cls == instance_cls, "");
+    BoxedInstance* inst = static_cast<BoxedInstance*>(_inst);
+
+    Box* getitem_func = _instanceGetattribute(inst, boxStrConstant("__getitem__"), true);
+    return runtimeCall(getitem_func, ArgPassSpec(1), key, NULL, NULL, NULL, NULL);
+}
+
+Box* instanceSetitem(Box* _inst, Box* key, Box* value) {
+    RELEASE_ASSERT(_inst->cls == instance_cls, "");
+    BoxedInstance* inst = static_cast<BoxedInstance*>(_inst);
+
+    Box* setitem_func = _instanceGetattribute(inst, boxStrConstant("__setitem__"), true);
+    return runtimeCall(setitem_func, ArgPassSpec(2), key, value, NULL, NULL, NULL);
+}
+
 void setupClassobj() {
     classobj_cls = new BoxedClass(type_cls, object_cls, &BoxedClassobj::gcHandler, offsetof(BoxedClassobj, attrs),
                                   sizeof(BoxedClassobj), false);
@@ -239,6 +266,9 @@ void setupClassobj() {
                            new BoxedFunction(boxRTFunction((void*)instanceGetattribute, UNKNOWN, 2)));
     instance_cls->giveAttr("__str__", new BoxedFunction(boxRTFunction((void*)instanceStr, UNKNOWN, 1)));
     instance_cls->giveAttr("__nonzero__", new BoxedFunction(boxRTFunction((void*)instanceNonzero, UNKNOWN, 1)));
+    instance_cls->giveAttr("__len__", new BoxedFunction(boxRTFunction((void*)instanceLen, UNKNOWN, 1)));
+    instance_cls->giveAttr("__getitem__", new BoxedFunction(boxRTFunction((void*)instanceGetitem, UNKNOWN, 2)));
+    instance_cls->giveAttr("__setitem__", new BoxedFunction(boxRTFunction((void*)instanceSetitem, UNKNOWN, 3)));
 
     instance_cls->freeze();
 }

test/tests/oldstyle_classes.py

@@ -44,10 +44,21 @@ class E():
     def __str__(self):
         return "E(%d)" % self.n
 
+    def __getitem__(self, x):
+        print "getitem"
+        return x
+
+    def __len__(self):
+        print "len"
+        return self.n
+
 e = E(1)
 print e
 print e.n
 print e.foo()
+print e[1]
+print e[1:2]
+print len(e)
 
 def str2():
     return "str2"
@@ -55,6 +66,7 @@ e.__str__ = str2
 print e
 
 print bool(e)
+print bool(E(0))
 print bool(E)
 
 class F:
@@ -66,3 +78,19 @@ class F:
 
 print bool(F(0))
 print bool(F(1))
+
+f = F(0)
+try:
+    len(f)
+except AttributeError, e:
+    print e
+
+try:
+    f[1]
+except AttributeError, e:
+    print e
+
+try:
+    f[1] = 2
+except AttributeError, e:
+    print e