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???)
diff --git a/Include/Python.h b/Include/Python.h
index b771c8c..2393872 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -82,6 +82,7 @@
#include "traceback.h"
#include "sliceobject.h"
#include "cellobject.h"
+#include "iterobject.h"
#include "codecs.h"
#include "pyerrors.h"
diff --git a/Include/abstract.h b/Include/abstract.h
index e0765e5..c56c887 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -470,6 +470,11 @@
*/
+ DL_IMPORT(PyObject *) PyObject_GetIter(PyObject *);
+ /* Takes an object and returns an iterator for it.
+ This is typically a new iterator but if the argument
+ is an iterator, this returns itself. */
+
/* Number Protocol:*/
DL_IMPORT(int) PyNumber_Check(PyObject *o);
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 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 @@
/* 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 @@
/* 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)
diff --git a/Include/opcode.h b/Include/opcode.h
index 546ad08..0cace8e 100644
--- a/Include/opcode.h
+++ b/Include/opcode.h
@@ -53,6 +53,7 @@
#define BINARY_XOR 65
#define BINARY_OR 66
#define INPLACE_POWER 67
+#define GET_ITER 68
#define PRINT_EXPR 70
#define PRINT_ITEM 71
@@ -80,6 +81,7 @@
#define STORE_NAME 90 /* Index in name list */
#define DELETE_NAME 91 /* "" */
#define UNPACK_SEQUENCE 92 /* Number of sequence items */
+#define FOR_ITER 93
#define STORE_ATTR 95 /* Index in name list */
#define DELETE_ATTR 96 /* "" */
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 622af2d..3c57e2f 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -24,6 +24,7 @@
/* Predefined exceptions */
extern DL_IMPORT(PyObject *) PyExc_Exception;
+extern DL_IMPORT(PyObject *) PyExc_StopIteration;
extern DL_IMPORT(PyObject *) PyExc_StandardError;
extern DL_IMPORT(PyObject *) PyExc_ArithmeticError;
extern DL_IMPORT(PyObject *) PyExc_LookupError;