Mercurial > cpython-lru_cache-weakref
diff Objects/rangeobject.c @ 31635:04eb2ebb46e2 legacy-trunk
Tidied up the implementations of reversed (including the custom ones
for xrange and list objects).
* list.__reversed__ now checks the length of the sequence object before
calling PyList_GET_ITEM() because the mutable could have changed length.
* all three implementations are now tranparent with respect to length and
maintain the invariant len(it) == len(list(it)) even when the underlying
sequence mutates.
* __builtin__.reversed() now frees the underlying sequence as soon
as the iterator is exhausted.
* the code paths were rearranged so that the most common paths
do not require a jump.
| author | Raymond Hettinger <python@rcn.com> |
|---|---|
| date | Wed, 10 Mar 2004 10:10:42 +0000 |
| parents | 41c4e143e6e6 |
| children | 0dc8ffaac036 |
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--- a/Objects/rangeobject.c Wed Mar 10 08:32:47 2004 +0000 +++ b/Objects/rangeobject.c Wed Mar 10 10:10:42 2004 +0000 @@ -288,6 +288,18 @@ return NULL; } +static int +rangeiter_len(rangeiterobject *r) +{ + return r->len - r->index; +} + +static PySequenceMethods rangeiter_as_sequence = { + (inquiry)rangeiter_len, /* sq_length */ + 0, /* sq_concat */ +}; + + static PyTypeObject Pyrangeiter_Type = { PyObject_HEAD_INIT(&PyType_Type) 0, /* ob_size */ @@ -302,7 +314,7 @@ 0, /* tp_compare */ 0, /* tp_repr */ 0, /* tp_as_number */ - 0, /* tp_as_sequence */ + &rangeiter_as_sequence, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ 0, /* tp_call */