Taylor Campbell wrote:
> There are some Lisp systems, such as CLISP and SISC (I believe), that
> allow arbitrary-precision flonums, the precision of which can be
> specified either through the operations used or by some fluid resource
> that controls the flonum operations.  Fast execution is not really an
> issue here; I think that there should be no reason to prohibit this
> kind of extension & to provide a way in code to specify IEEE behaviour
> explicitly if so desired.  Not only is it more flexible to do that,
> but it also makes the intent of programs clearer.

Lots of interesting stuff:
http://www2.hursley.ibm.com/decimal/

The proposed formats, including the arbitrary-precision variants,
do include NaNs.  E.g.:
http://www2.hursley.ibm.com/decimal/dnintro.html
http://www2.hursley.ibm.com/deceou/decsample/src/com/ibm/eou/decimal/ModelNumber.java
--
	--Per Bothner
xxxxxx@bothner.com   http://per.bothner.com/