Mercurial > cpython-lru_cache-weakref
annotate Python/fmod.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 | 6f6f965c5e2d |
| children | 2dea40e40d9d |
| rev | line source |
|---|---|
| 145 | 1 |
| 6 | 2 /* Portable fmod(x, y) implementation for systems that don't have it */ |
| 3 | |
| 2434 | 4 #include "config.h" |
| 5 | |
|
13761
59f8cedcf049
merge Include/my*.h into Include/pyport.h
Peter Schneider-Kamp <nowonder@nowonder.de>
parents:
13256
diff
changeset
|
6 #include "pyport.h" |
| 6 | 7 #include <errno.h> |
| 8 | |
| 9 double | |
| 2434 | 10 fmod(double x, double y) |
| 6 | 11 { |
| 12 double i, f; | |
| 13 | |
| 14 if (y == 0.0) { | |
| 15 errno = EDOM; | |
| 16 return 0.0; | |
| 17 } | |
| 18 | |
| 19 /* return f such that x = i*y + f for some integer i | |
| 20 such that |f| < |y| and f has the same sign as x */ | |
| 21 | |
| 22 i = floor(x/y); | |
| 23 f = x - i*y; | |
| 24 if ((x < 0.0) != (y < 0.0)) | |
| 25 f = f-y; | |
| 26 return f; | |
| 27 } |