Re: openr and /get_lun

["Joseph B. Gurman" <gurman(at)gsfc.nasa.gov>]

In article <8dfqbo$ep1$2@hammer.msfc.nasa.gov>, 
mallors@ips1.msfc.nasa.gov (Robert S. Mallozzi) wrote:

> In article <38FB4B75.936477C5@astro.cornell.edu>,
> 	"J.D. Smith" <jdsmith@astro.cornell.edu> writes:
> > "Robert S. Mallozzi" wrote:
> >> 
> >> I sure wish we had a boolean datatype - the mistake of
> >> using something like "IF (NOT error) THEN" is one that
> >> is really a pain to find, although it certainly makes
> >> your code much more readable.
> > 
> > We don't need a boolean data type... we need IF to examine not just the 
> > first
> > bit of the value, but the whole thing, and use C's 0=false, anything 
> > else =true
> > paradigm.  Here's hoping.
> > 
> > if NOT 2 then print,"this isn't right!"
>  
>  
> This would certainly break backward compatibility - there 
> has to be someone, somewhere that relies on the fact that in
> IDL, odd = true and even = false !  I feel as you do that this 
> was a design mistake made a long time ago, in a programmer's
> mind far, far away...
> 
> Regards,
> 
> -bob


    One man's mistake is another's feature (or something like that).

    The "low bit 0 = false, low bit = 1 true" convention is from VMS 
(way back in the pre-Alpha days, even.... what did they call those 
things, VAXen? VAXes?), with the more significant bits yielding addition 
information on the specific error or (in the case of oddness) warning, 
&c.

    No doubt due to operant conditioning programming VAX system 
services, I find this convention more useful than C's convention.

    Chacun a son error convention....

                  Joe Gurman

-- 
Joseph B. Gurman / NASA Goddard Space Flight Center / Solar Physics Branch /
Greenbelt MD 20771 / work: gurman@gsfc.nasa.gov /other: gurman@ari.net

Government employees are still not allowed to hold opinions while at work,
so any opinions expressed herein must be someone else's.