[Openmcl-devel] Printing/reading INF and NaN without #<> or #.

Dan Corkill dancorkill at comcast.net
Sat Nov 12 19:29:39 UTC 2005


OpenMCL currently uses a non-readable #<> notation to textually represent
IEEE 754 
infinite values.  We needed to be able to print/read these values without
*read-eval* enabled.  Lispworks uses a simple, extended number
syntax to encode IEEE 754 values (e.g., 1e++0 for INF) that we like as
a convenient textual representation.  Modified OpenMCL 1.0
functions that provide this extended-syntax support for INF, -INF,
and NaN can be found at:
http://dancorkill.home.comcast.net/openmcl-inf.lisp
(Sorry, I don't have these as patches to the development sources.)

We'd like to see this "extended" number syntax more widely
adopted (allowing infinite values to be portably exchanged
among CL implementations that support 754).  [No IEEE 754
advantage/disadvantage debates, please!]

-- Dan Corkill




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