Mercurial > cpython-lru_cache-weakref
diff Python/ceval.c @ 17597:32e7d0898eab legacy-trunk
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???)
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Fri, 20 Apr 2001 19:13:02 +0000 |
| parents | a34293ced63b |
| children | 1fe8e50e6e1b |
line wrap: on
line diff
--- a/Python/ceval.c Fri Apr 20 19:04:55 2001 +0000 +++ b/Python/ceval.c Fri Apr 20 19:13:02 2001 +0000 @@ -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.