Extend function() to support an optional closure argument.
Also, simplify some ref counting for other optional arguments.
diff --git a/Lib/test/test_new.py b/Lib/test/test_new.py
index 641d9c2..eb762f7 100644
--- a/Lib/test/test_new.py
+++ b/Lib/test/test_new.py
@@ -71,6 +71,30 @@
verify(g['c'] == 3,
'Could not create a proper function object')
+# test the various extended flavors of function.new
+def f(x):
+ def g(y):
+ return x + y
+ return g
+g = f(4)
+new.function(f.func_code, {}, "blah")
+g2 = new.function(g.func_code, {}, "blah", (2,), g.func_closure)
+verify(g2() == 6)
+g3 = new.function(g.func_code, {}, "blah", None, g.func_closure)
+verify(g3(5) == 9)
+def test_closure(func, closure, exc):
+ try:
+ new.function(func.func_code, {}, "", None, closure)
+ except exc:
+ pass
+ else:
+ print "corrupt closure accepted"
+
+test_closure(g, None, TypeError) # invalid closure
+test_closure(g, (1,), TypeError) # non-cell in closure
+test_closure(g, (1, 1), ValueError) # closure is wrong size
+test_closure(f, g.func_closure, ValueError) # no closure needed
+
print 'new.code()'
# bogus test of new.code()
# Note: Jython will never have new.code()
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 4eac035..4f36df9 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -267,47 +267,100 @@
};
PyDoc_STRVAR(func_doc,
-"function(code, globals[, name[, argdefs]])\n\
+"function(code, globals[, name[, argdefs[, closure]]])\n\
\n\
Create a function object from a code object and a dictionary.\n\
The optional name string overrides the name from the code object.\n\
-The optional argdefs tuple specifies the default argument values.");
+The optional argdefs tuple specifies the default argument values.\n\
+The optional closure tuple supplies the bindings for free variables.");
+
+/* func_new() maintains the following invariants for closures. The
+ closure must correspond to the free variables of the code object.
+
+ if len(code.co_freevars) == 0:
+ closure = NULL
+ else:
+ len(closure) == len(code.co_freevars)
+ for every elt in closure, type(elt) == cell
+*/
static PyObject *
func_new(PyTypeObject* type, PyObject* args, PyObject* kw)
{
- PyObject *code;
+ PyCodeObject *code;
PyObject *globals;
PyObject *name = Py_None;
PyObject *defaults = Py_None;
+ PyObject *closure = Py_None;
PyFunctionObject *newfunc;
+ int nfree, nclosure;
- if (!PyArg_ParseTuple(args, "O!O!|OO!:function",
+ if (!PyArg_ParseTuple(args, "O!O!|OOO:function",
&PyCode_Type, &code,
&PyDict_Type, &globals,
- &name,
- &PyTuple_Type, &defaults))
+ &name, &defaults, &closure))
return NULL;
if (name != Py_None && !PyString_Check(name)) {
PyErr_SetString(PyExc_TypeError,
"arg 3 (name) must be None or string");
return NULL;
}
+ if (defaults != Py_None && !PyTuple_Check(defaults)) {
+ PyErr_SetString(PyExc_TypeError,
+ "arg 4 (defaults) must be None or tuple");
+ return NULL;
+ }
+ nfree = PyTuple_GET_SIZE(code->co_freevars);
+ if (!PyTuple_Check(closure)) {
+ if (nfree && closure == Py_None) {
+ PyErr_SetString(PyExc_TypeError,
+ "arg 5 (closure) must be tuple");
+ return NULL;
+ }
+ else if (closure != Py_None) {
+ PyErr_SetString(PyExc_TypeError,
+ "arg 5 (closure) must be None or tuple");
+ return NULL;
+ }
+ }
- newfunc = (PyFunctionObject *)PyFunction_New(code, globals);
+ /* check that the closure is well-formed */
+ nclosure = closure == Py_None ? 0 : PyTuple_GET_SIZE(closure);
+ if (nfree != nclosure)
+ return PyErr_Format(PyExc_ValueError,
+ "%s requires closure of length %d, not %d",
+ PyString_AS_STRING(code->co_name),
+ nfree, nclosure);
+ if (nclosure) {
+ int i;
+ for (i = 0; i < nclosure; i++) {
+ PyObject *o = PyTuple_GET_ITEM(closure, i);
+ if (!PyCell_Check(o)) {
+ return PyErr_Format(PyExc_TypeError,
+ "arg 5 (closure) expected cell, found %s",
+ o->ob_type->tp_name);
+ }
+ }
+ }
+
+ newfunc = (PyFunctionObject *)PyFunction_New((PyObject *)code,
+ globals);
if (newfunc == NULL)
return NULL;
-
+
if (name != Py_None) {
- Py_XINCREF(name);
- Py_XDECREF(newfunc->func_name);
+ Py_INCREF(name);
+ Py_DECREF(newfunc->func_name);
newfunc->func_name = name;
}
if (defaults != Py_None) {
- Py_XINCREF(defaults);
- Py_XDECREF(newfunc->func_defaults);
+ Py_INCREF(defaults);
newfunc->func_defaults = defaults;
}
+ if (closure != Py_None) {
+ Py_INCREF(closure);
+ newfunc->func_closure = closure;
+ }
return (PyObject *)newfunc;
}