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Iterators phase 1. This comprises:

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

24
Python/compile.c
View file

@ -1232,21 +1232,15 @@ parsestrplus(node *n)
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_list_for(struct compiling *c, node *n, node *e, char *t)
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 @@ com_while_stmt(struct compiling *c, node *n)
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_for_stmt(struct compiling *c, node *n)
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_for_stmt(struct compiling *c, node *n)
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)