comp.lang.idl-pvwave archive: archive » openr and /get

Home » Public Forums » archive » openr and /get_lun

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: openr and /get_lun [message #19830 is a reply to message #19741]

Thu, 20 April 2000 00:00

Joseph B. Gurman
Messages: 31
Registered: April 2000

Member

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.

Report message to a moderator

[Message index]

		openr and /get_lun By: Craig Markwardt on Fri, 14 April 2000 00:00
		Re: openr and /get_lun By: Joseph B. Gurman on Thu, 20 April 2000 00:00
		Re: openr and /get_lun By: John-David T. Smith on Mon, 17 April 2000 00:00
		Re: openr and /get_lun By: mallors on Mon, 17 April 2000 00:00
		Re: openr and /get_lun By: mallors on Mon, 17 April 2000 00:00
		Re: openr and /get_lun By: Craig Markwardt on Mon, 17 April 2000 00:00
		Re: openr and /get_lun By: John-David T. Smith on Mon, 17 April 2000 00:00

Previous Topic:	how to read GRIB format data (NCEP monthly U/VFlux data)
Next Topic:	Theater Arts 101: Intro to Lighting Design

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Thu Oct 09 21:57:08 PDT 2025

Total time taken to generate the page: 0.63844 seconds