On Mon, Nov 9, 2009 at 1:01 PM, Mark Dickinson <dicki...@gmail.com> wrote: > current behaviour comes from the IEEE 854 standard; given the > absence of helpful information in the Decimal standard, IEEE 854 > is an obvious next place to look. There's an unofficial copy of the > standard available at: > > http://754r.ucbtest.org/standards/854.pdf > > Section 5.7 describes twenty-six(!) distinct comparison operators.
It's interesting to note that out of the 32 possible different comparison behaviours (two choices of result for each of {equal, lessthan, greaterthan, unordered}, together with a choice of whether to signal or not for unordered in each case), the two interesting operators that are missing from that IEEE 854 table are precisely the ones that we're discussing: signalling __eq__ (i.e., return False for lessthan, greaterthan, unordered, True for equal, and signal on unordered), and signalling __ne__ (the reverse of the above, but still signalling on unordered). (The other four missing operators are the uninteresting ones that always return True or always return False.) Mark _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com