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???)
This commit is contained in:
Guido van Rossum 2001-04-20 19:13:02 +00:00
parent 12e73bb2f0
commit 59d1d2b434
16 changed files with 256 additions and 25 deletions

View file

@ -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)