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;
diff --git a/Lib/dis.py b/Lib/dis.py
index dc30257..fb97369 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -205,6 +205,7 @@
def_op('BINARY_XOR', 65)
def_op('BINARY_OR', 66)
def_op('INPLACE_POWER', 67)
+def_op('GET_ITER', 68)
def_op('PRINT_EXPR', 70)
def_op('PRINT_ITEM', 71)
@@ -232,6 +233,7 @@
name_op('STORE_NAME', 90) # Index in name list
name_op('DELETE_NAME', 91) # ""
def_op('UNPACK_SEQUENCE', 92) # Number of tuple items
+def_op('FOR_ITER', 93)
name_op('STORE_ATTR', 95) # Index in name list
name_op('DELETE_ATTR', 96) # ""
diff --git a/Makefile.pre.in b/Makefile.pre.in
index f2f3336..103a36b 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -238,6 +238,7 @@
Objects/frameobject.o \
Objects/funcobject.o \
Objects/intobject.o \
+ Objects/iterobject.o \
Objects/listobject.o \
Objects/longobject.o \
Objects/dictobject.o \
@@ -433,6 +434,7 @@
Include/bufferobject.h \
Include/tupleobject.h \
Include/listobject.h \
+ Include/iterobject.h \
Include/dictobject.h \
Include/methodobject.h \
Include/moduleobject.h \
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 3ccac71..8a6df76 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1738,3 +1738,20 @@
return retval;
}
+
+PyObject *
+PyObject_GetIter(PyObject *o)
+{
+ PyTypeObject *t = o->ob_type;
+ getiterfunc f = NULL;
+ if (PyType_HasFeature(t, Py_TPFLAGS_HAVE_ITER))
+ f = t->tp_iter;
+ if (f == NULL) {
+ if (PySequence_Check(o))
+ return PyIter_New(o);
+ PyErr_SetString(PyExc_TypeError, "iter() of non-sequence");
+ return NULL;
+ }
+ else
+ return (*f)(o);
+}
diff --git a/Objects/classobject.c b/Objects/classobject.c
index fa71c4e..742e472 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -848,7 +848,7 @@
return 0;
}
-static PyObject *getitemstr, *setitemstr, *delitemstr, *lenstr;
+static PyObject *getitemstr, *setitemstr, *delitemstr, *lenstr, *iterstr;
static int
instance_length(PyInstanceObject *inst)
@@ -1712,6 +1712,32 @@
}
+/* Get the iterator */
+static PyObject *
+instance_getiter(PyInstanceObject *self)
+{
+ PyObject *func;
+
+ if (iterstr == NULL)
+ iterstr = PyString_InternFromString("__iter__");
+ if (getitemstr == NULL)
+ getitemstr = PyString_InternFromString("__getitem__");
+
+ if ((func = instance_getattr(self, iterstr)) != NULL) {
+ PyObject *res = PyEval_CallObject(func, (PyObject *)NULL);
+ Py_DECREF(func);
+ return res;
+ }
+ PyErr_Clear();
+ if ((func = instance_getattr(self, getitemstr)) == NULL) {
+ PyErr_SetString(PyExc_TypeError, "iter() of non-sequence");
+ return NULL;
+ }
+ Py_DECREF(func);
+ return PyIter_New((PyObject *)self);
+}
+
+
static PyNumberMethods instance_as_number = {
(binaryfunc)instance_add, /* nb_add */
(binaryfunc)instance_sub, /* nb_subtract */
@@ -1775,7 +1801,8 @@
(traverseproc)instance_traverse, /* tp_traverse */
0, /* tp_clear */
instance_richcompare, /* tp_richcompare */
- offsetof(PyInstanceObject, in_weakreflist) /* tp_weaklistoffset */
+ offsetof(PyInstanceObject, in_weakreflist), /* tp_weaklistoffset */
+ (getiterfunc)instance_getiter, /* tp_iter */
};
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 95d5b71..17b6a04 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1324,6 +1324,8 @@
0, /* sq_inplace_repeat */
};
+staticforward PyObject *dictiter_new(dictobject *);
+
PyTypeObject PyDict_Type = {
PyObject_HEAD_INIT(&PyType_Type)
0,
@@ -1350,6 +1352,8 @@
(traverseproc)dict_traverse, /* tp_traverse */
(inquiry)dict_tp_clear, /* tp_clear */
0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ (getiterfunc)dictiter_new, /* tp_iter */
};
/* For backward compatibility with old dictionary interface */
@@ -1392,3 +1396,102 @@
Py_DECREF(kv);
return err;
}
+
+/* Dictionary iterator type */
+
+extern PyTypeObject PyDictIter_Type; /* Forward */
+
+typedef struct {
+ PyObject_HEAD
+ dictobject *di_dict;
+ int di_size;
+ int di_pos;
+} dictiterobject;
+
+static PyObject *
+dictiter_new(dictobject *dict)
+{
+ dictiterobject *di;
+ di = PyObject_NEW(dictiterobject, &PyDictIter_Type);
+ if (di == NULL)
+ return NULL;
+ Py_INCREF(dict);
+ di->di_dict = dict;
+ di->di_size = dict->ma_size;
+ di->di_pos = 0;
+ return (PyObject *)di;
+}
+
+static void
+dictiter_dealloc(dictiterobject *di)
+{
+ Py_DECREF(di->di_dict);
+ PyObject_DEL(di);
+}
+
+static PyObject *
+dictiter_next(dictiterobject *di, PyObject *args)
+{
+ PyObject *key;
+ if (di->di_size != di->di_dict->ma_size) {
+ PyErr_SetString(PyExc_RuntimeError,
+ "dictionary changed size during iteration");
+ return NULL;
+ }
+ if (PyDict_Next((PyObject *)(di->di_dict), &di->di_pos, &key, NULL)) {
+ Py_INCREF(key);
+ return key;
+ }
+ PyErr_SetObject(PyExc_StopIteration, Py_None);
+ return NULL;
+}
+
+static PyObject *
+dictiter_getiter(PyObject *it)
+{
+ Py_INCREF(it);
+ return it;
+}
+
+static PyMethodDef dictiter_methods[] = {
+ {"next", (PyCFunction)dictiter_next, METH_VARARGS,
+ "it.next() -- get the next value, or raise StopIteration"},
+ {NULL, NULL} /* sentinel */
+};
+
+static PyObject *
+dictiter_getattr(dictiterobject *it, char *name)
+{
+ return Py_FindMethod(dictiter_methods, (PyObject *)it, name);
+}
+
+PyTypeObject PyDictIter_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* ob_size */
+ "dictionary-iterator", /* tp_name */
+ sizeof(dictiterobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)dictiter_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ (getattrfunc)dictiter_getattr, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ 0, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT, /* tp_flags */
+ 0, /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ (getiterfunc)dictiter_getiter, /* tp_iter */
+};
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 1701b2f..861cade 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -3232,6 +3232,8 @@
void _Py_ReleaseInternedStrings(void)
{
if (interned) {
+ fprintf(stderr, "releasing interned strings\n");
+ PyDict_Clear(interned);
Py_DECREF(interned);
interned = NULL;
}
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 576447c..7e8f555 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1312,6 +1312,32 @@
static PyObject *
+builtin_iter(PyObject *self, PyObject *args)
+{
+ PyObject *v, *w = NULL;
+
+ if (!PyArg_ParseTuple(args, "O|O:iter", &v, &w))
+ return NULL;
+ if (w == NULL)
+ return PyObject_GetIter(v);
+ if (!PyCallable_Check(v)) {
+ PyErr_SetString(PyExc_TypeError,
+ "iter(v, w): v must be callable");
+ return NULL;
+ }
+ return PyCallIter_New(v, w);
+}
+
+static char iter_doc[] =
+"iter(collection) -> iterator\n\
+iter(callable, sentinel) -> iterator\n\
+\n\
+Get an iterator from an object. In the first form, the argument must\n\
+supply its own iterator, or be a sequence.\n\
+In the second form, the callable is called until it returns the sentinel.";
+
+
+static PyObject *
builtin_len(PyObject *self, PyObject *args)
{
PyObject *v;
@@ -2148,6 +2174,7 @@
{"int", builtin_int, 1, int_doc},
{"isinstance", builtin_isinstance, 1, isinstance_doc},
{"issubclass", builtin_issubclass, 1, issubclass_doc},
+ {"iter", builtin_iter, 1, iter_doc},
{"len", builtin_len, 1, len_doc},
{"list", builtin_list, 1, list_doc},
{"locals", builtin_locals, 1, locals_doc},
diff --git a/Python/ceval.c b/Python/ceval.c
index b6686b6..4f4a646 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -381,6 +381,7 @@
/* Make it easier to find out where we are with a debugger */
char *filename = PyString_AsString(co->co_filename);
#endif
+ static PyObject *nextstr;
/* Code access macros */
@@ -416,6 +417,11 @@
GETLOCAL(i) = value; } while (0)
/* Start of code */
+ if (nextstr == NULL) {
+ nextstr = PyString_InternFromString("next");
+ if (nextstr == NULL)
+ return NULL;
+ }
#ifdef USE_STACKCHECK
if (tstate->recursion_depth%10 == 0 && PyOS_CheckStack()) {
@@ -1875,6 +1881,41 @@
JUMPTO(oparg);
continue;
+ case GET_ITER:
+ /* before: [obj]; after [getiter(obj)] */
+ v = POP();
+ x = PyObject_GetIter(v);
+ Py_DECREF(v);
+ if (x != NULL) {
+ w = x;
+ x = PyObject_GetAttr(w, nextstr);
+ Py_DECREF(w);
+ if (x != NULL) {
+ PUSH(x);
+ continue;
+ }
+ }
+ break;
+
+ case FOR_ITER:
+ /* before: [iter]; after: [iter, iter()] *or* [] */
+ v = TOP();
+ x = PyObject_CallObject(v, NULL);
+ if (x == NULL) {
+ if (PyErr_ExceptionMatches(
+ PyExc_StopIteration))
+ {
+ PyErr_Clear();
+ x = v = POP();
+ Py_DECREF(v);
+ JUMPBY(oparg);
+ continue;
+ }
+ break;
+ }
+ PUSH(x);
+ continue;
+
case FOR_LOOP:
/* for v in s: ...
On entry: stack contains s, i.
diff --git a/Python/compile.c b/Python/compile.c
index 0939f05..cb85ce3 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1232,21 +1232,15 @@
static void
com_list_for(struct compiling *c, node *n, node *e, char *t)
{
- PyObject *v;
int anchor = 0;
int save_begin = c->c_begin;
/* list_iter: for v in expr [list_iter] */
com_node(c, CHILD(n, 3)); /* expr */
- v = PyInt_FromLong(0L);
- if (v == NULL)
- c->c_errors++;
- com_addoparg(c, LOAD_CONST, com_addconst(c, v));
- com_push(c, 1);
- Py_XDECREF(v);
+ com_addbyte(c, GET_ITER);
c->c_begin = c->c_nexti;
com_addoparg(c, SET_LINENO, n->n_lineno);
- com_addfwref(c, FOR_LOOP, &anchor);
+ com_addfwref(c, FOR_ITER, &anchor);
com_push(c, 1);
com_assign(c, CHILD(n, 1), OP_ASSIGN, NULL);
c->c_loops++;
@@ -1255,7 +1249,7 @@
com_addoparg(c, JUMP_ABSOLUTE, c->c_begin);
c->c_begin = save_begin;
com_backpatch(c, anchor);
- com_pop(c, 2); /* FOR_LOOP has popped these */
+ com_pop(c, 1); /* FOR_ITER has popped this */
}
static void
@@ -2873,7 +2867,6 @@
static void
com_for_stmt(struct compiling *c, node *n)
{
- PyObject *v;
int break_anchor = 0;
int anchor = 0;
int save_begin = c->c_begin;
@@ -2882,15 +2875,10 @@
com_addfwref(c, SETUP_LOOP, &break_anchor);
block_push(c, SETUP_LOOP);
com_node(c, CHILD(n, 3));
- v = PyInt_FromLong(0L);
- if (v == NULL)
- c->c_errors++;
- com_addoparg(c, LOAD_CONST, com_addconst(c, v));
- com_push(c, 1);
- Py_XDECREF(v);
+ com_addbyte(c, GET_ITER);
c->c_begin = c->c_nexti;
com_addoparg(c, SET_LINENO, n->n_lineno);
- com_addfwref(c, FOR_LOOP, &anchor);
+ com_addfwref(c, FOR_ITER, &anchor);
com_push(c, 1);
com_assign(c, CHILD(n, 1), OP_ASSIGN, NULL);
c->c_loops++;
@@ -2899,7 +2887,7 @@
com_addoparg(c, JUMP_ABSOLUTE, c->c_begin);
c->c_begin = save_begin;
com_backpatch(c, anchor);
- com_pop(c, 2); /* FOR_LOOP has popped these */
+ com_pop(c, 1); /* FOR_ITER has popped this */
com_addbyte(c, POP_BLOCK);
block_pop(c, SETUP_LOOP);
if (NCH(n) > 8)
diff --git a/Python/exceptions.c b/Python/exceptions.c
index ad8021e..214d8e5 100644
--- a/Python/exceptions.c
+++ b/Python/exceptions.c
@@ -52,6 +52,7 @@
Exception\n\
|\n\
+-- SystemExit\n\
+ +-- StopIteration\n\
+-- StandardError\n\
| |\n\
| +-- KeyboardInterrupt\n\
@@ -369,6 +370,9 @@
static char
TypeError__doc__[] = "Inappropriate argument type.";
+static char
+StopIteration__doc__[] = "Signal the end from iterator.next().";
+
static char
@@ -924,6 +928,7 @@
/* Global C API defined exceptions */
PyObject *PyExc_Exception;
+PyObject *PyExc_StopIteration;
PyObject *PyExc_StandardError;
PyObject *PyExc_ArithmeticError;
PyObject *PyExc_LookupError;
@@ -985,6 +990,8 @@
* The first three classes MUST appear in exactly this order
*/
{"Exception", &PyExc_Exception},
+ {"StopIteration", &PyExc_StopIteration, &PyExc_Exception,
+ StopIteration__doc__},
{"StandardError", &PyExc_StandardError, &PyExc_Exception,
StandardError__doc__},
{"TypeError", &PyExc_TypeError, 0, TypeError__doc__},
diff --git a/Python/import.c b/Python/import.c
index bde49ce..2c15d10 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -43,7 +43,7 @@
/* XXX Perhaps the magic number should be frozen and a version field
added to the .pyc file header? */
/* New way to come up with the magic number: (YEAR-1995), MONTH, DAY */
-#define MAGIC (60202 | ((long)'\r'<<16) | ((long)'\n'<<24))
+#define MAGIC (60420 | ((long)'\r'<<16) | ((long)'\n'<<24))
/* Magic word as global; note that _PyImport_Init() can change the
value of this global to accommodate for alterations of how the