[Python-checkins] CVS: python/dist/src/Doc/ext newtypes.tex,1.3,1.4

[Guido van Rossum]

Update of /cvsroot/python/python/dist/src/Doc/ext
In directory usw-pr-cvs1:/tmp/cvs-serv18927

Modified Files:
	newtypes.tex 
Log Message:
Document required return values -1, 0, 1 for tp_compare handler, as
suggested in SF patch #424475.  Also document exception return.


Index: newtypes.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/ext/newtypes.tex,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** newtypes.tex	2001/09/26 22:26:45	1.3
--- newtypes.tex	2001/10/16 20:32:05	1.4
***************
*** 623,630 ****
  functions are used, or if \function{cmp()} is used from Python.)
  It is analogous to the \method{__cmp__()} method.  This function
! should return a negative integer if \var{obj1} is less than
! \var{obj2}, \code{0} if they are equal, and a positive integer if
  \var{obj1} is greater than
  \var{obj2}.
  
  Here is a sample implementation:
--- 623,639 ----
  functions are used, or if \function{cmp()} is used from Python.)
  It is analogous to the \method{__cmp__()} method.  This function
! should return \code{-1} if \var{obj1} is less than
! \var{obj2}, \code{0} if they are equal, and \code{1} if
  \var{obj1} is greater than
  \var{obj2}.
+ (It was previously allowed to return arbitrary negative or positive
+ integers for less than and greater than, respectively; as of Python
+ 2.2, this is no longer allowed.  In the future, other return values
+ may be assigned a different meaning.)
+ 
+ A \member{tp_compare} handler may raise an exception.  In this case it
+ should return a negative value.  The caller has to test for the
+ exception using \cfunction{PyErr_Occurred()}.
+ 
  
  Here is a sample implementation: