[Python-checkins] python/dist/src/Misc NEWS,1.934,1.935

Sat Feb 14 23:06:44 EST 2004

Update of /cvsroot/python/python/dist/src/Misc
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv4496
Modified Files:
	NEWS 
Log Message:
* Moved the responsibility for emptying the previous list from list_fill
 to list_init.
* Replaced the code in list_extend with the superior code from list_fill.
* Eliminated list_fill.
Results:
* list.extend() no longer creates an intermediate tuple except to handle
 the special case of x.extend(x). The saves memory and time.
* list.extend(x) runs
 about the same x is a list or tuple,
 a little faster when x is an iterable not defining __len__, and
 twice as fast when x is an iterable defining __len__.
 
* the code is about 15 lines shorter and no longer duplicates
 functionality.
Index: NEWS
===================================================================
RCS file: /cvsroot/python/python/dist/src/Misc/NEWS,v
retrieving revision 1.934
retrieving revision 1.935
diff -C2 -d -r1.934 -r1.935
*** NEWS	14 Feb 2004 18:34:46 -0000	1.934
--- NEWS	15 Feb 2004 04:06:39 -0000	1.935
***************
*** 13,16 ****
--- 13,21 ----
 -----------------
 
+ - Optimized list.extend() to save memory and no longer create
+ intermediate sequences. Also, extend() now pre-allocates the
+ needed memory whenever the length of the iterable is known in
+ advance -- this halves the time to extend the list.
+ 
 - Optimized list resize operations to make fewer calls to the system
 realloc(). Significantly speeds up list appends, list pops,