Merge pull request #429 from adrian17/master

Fix callable(), add tests.

tests/snippets/builtin_callable.py

@@ -0,0 +1,26 @@
+assert not callable(1)
+def f(): pass
+# TODO uncomment when callable types get unified __call__ (or equivalent)
+#assert callable(f)
+#assert callable(len)
+#assert callable(lambda: 1)
+assert callable(int)
+
+class C:
+    def __init__(self):
+        # must be defined on class
+        self.__call__ = lambda self: 1
+    def f(self): pass
+assert callable(C)
+assert not callable(C())
+#assert callable(C().f)
+
+class C:
+    def __call__(self): pass
+assert callable(C())
+class C1(C): pass
+assert callable(C1())
+class C:
+    __call__ = 1
+# CPython returns true here, but fails when actually calling it
+assert callable(C())

tests/snippets/weakrefs.py

@@ -8,5 +8,6 @@ class X:
 a = X()
 b = ref(a)
 
+assert callable(b)
 assert b() is a
 

vm/src/builtins.rs

@@ -101,8 +101,7 @@ fn builtin_bin(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 fn builtin_callable(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(obj, None)]);
-    // TODO: is this a sufficiently thorough check?
-    let is_callable = obj.has_attr("__call__");
+    let is_callable = obj.typ().has_attr("__call__");
     Ok(vm.new_bool(is_callable))
 }