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Re: reading NaNs



   Date: Wed, 26 Oct 2005 16:10:20 -0400
   From: "John.Cowan" <jcowan@xxxxxxxxxxxxxxxxx>

   Thomas Bushnell BSG scripsit:

   > How about the user expects that, if he has requested an
   > IEEE-conformant environment, he will get it?

   Could you explain the concrete benefits of having a flonum system
   available which is non-IIEEE?  (Fast execution on processors which
   provide hardware flonums that are non-IEEE, now extremely rare, excepted.)

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.