Re: _ref_extra

[JD Smith <jdsmith(at)astro.cornell.edu>]

"Pavel A. Romashkin" wrote:
> 
> Doe anybody know if there is a way to get into the "IDL maintained"
> values managed by _ref_extra, which are then passed by _extra to be
> returned by reference? Like an _extra structure can be analyzed in a
> program? I can't seem to me able to get anywhere with a string array
> returned by _ref_extra :-(
> Thenk you,
> Pavel

Nope, not a chance.  Part of the mechanism used by _REF_EXTRA assumes
the routine declaring it is only interested in passing keywords onward,
not in inspecting them in the meantime.  This is an assumption which, if
it had been true for _EXTRA itself, would have meant no aditional
keyword was required for pass-by-reference keyword inheritance.  I
debated the topic in the newsgroup from the earliest days of
_REF_EXTRA.  

Here's the commentary which led to it's introduction:

http://groups.google.com/groups?selm=33E767F4.74F051BF%40astrosun.tn.cornell.edu

Here's the relevant thread discussing the details of the mechanism:

http://groups.google.com/groups?hl=en&safe=off&th=c24a35463d38e145,5&seekm=355A0AFC.DF2B53D8%40astrosun.tn.cornell.edu#p

A good read for a lazy Friday.

JD