Iterators phase 1. This comprises:

new slot tp_iter in type object, plus new flag Py_TPFLAGS_HAVE_ITER
new C API PyObject_GetIter(), calls tp_iter
new builtin iter(), with two forms: iter(obj), and iter(function, sentinel)
new internal object types iterobject and calliterobject
new exception StopIteration
new opcodes for "for" loops, GET_ITER and FOR_ITER (also supported by dis.py)
new magic number for .pyc files
new special method for instances: __iter__() returns an iterator
iteration over dictionaries: "for x in dict" iterates over the keys
iteration over files: "for x in file" iterates over lines

TODO:

documentation
test suite
decide whether to use a different way to spell iter(function, sentinal)
decide whether "for key in dict" is a good idea
use iterators in map/filter/reduce, min/max, and elsewhere (in/not in?)
speed tuning (make next() a slot tp_next???)

1 files changed, 10 insertions, 4 deletions

diff --git a/Include/object.h b/Include/object.h
index 80669da..4a53835 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -200,6 +200,7 @@ typedef int (*cmpfunc)(PyObject *, PyObject *);
 typedef PyObject *(*reprfunc)(PyObject *);
 typedef long (*hashfunc)(PyObject *);
 typedef PyObject *(*richcmpfunc) (PyObject *, PyObject *, int);
+typedef PyObject *(*getiterfunc) (PyObject *);
 
 typedef struct _typeobject {
 	PyObject_VAR_HEAD
@@ -249,8 +250,11 @@ typedef struct _typeobject {
 	/* weak reference enabler */
 	long tp_weaklistoffset;
 
+	/* Iterators */
+	getiterfunc tp_iter;
+
 #ifdef COUNT_ALLOCS
-	/* these must be last */
+	/* these must be last and never explicitly initialized */
 	int tp_alloc;
 	int tp_free;
 	int tp_maxalloc;
@@ -342,20 +346,22 @@ given type object has a specified feature.
 /* PyNumberMethods do their own coercion */
 #define Py_TPFLAGS_CHECKTYPES (1L<<4)
 
+/* tp_richcompare is defined */
 #define Py_TPFLAGS_HAVE_RICHCOMPARE (1L<<5)
 
 /* Objects which are weakly referencable if their tp_weaklistoffset is >0 */
-/* XXX Should this have the same value as Py_TPFLAGS_HAVE_RICHCOMPARE?
- * These both indicate a feature that appeared in the same alpha release.
- */
 #define Py_TPFLAGS_HAVE_WEAKREFS (1L<<6)
 
+/* tp_iter is defined */
+#define Py_TPFLAGS_HAVE_ITER (1L<<7)
+
 #define Py_TPFLAGS_DEFAULT  ( \
                              Py_TPFLAGS_HAVE_GETCHARBUFFER | \
                              Py_TPFLAGS_HAVE_SEQUENCE_IN | \
                              Py_TPFLAGS_HAVE_INPLACEOPS | \
                              Py_TPFLAGS_HAVE_RICHCOMPARE | \
                              Py_TPFLAGS_HAVE_WEAKREFS | \
+                             Py_TPFLAGS_HAVE_ITER | \
                             0)
 
 #define PyType_HasFeature(t,f)  (((t)->tp_flags & (f)) != 0)