[OE-core] some simple questions about assignment and appending

[Christopher Larson]

The only assignment operator that forces immediate expansion is :=. Otherwise expansion always occurs when the value is used. This is inspired by the behavior of GNU Make. See http://www.gnu.org/software/make/manual/html_node/Flavors.html#Flavors for details of how it works there.

-- 
Christopher Larson


On Tuesday, June 19, 2012 at 1:49 PM, Robert P. J. Day wrote:

> On Tue, 19 Jun 2012, Paul Eggleton wrote:
> 
> > On Tuesday 19 June 2012 12:28:22 Robert P. J. Day wrote:
> > 
> > > finally, what are the evaluation mechanics of the "?=" operator?
> > 
> > ?= is the same as = except that it only sets the value if it is not
> > already set at the time the line is parsed.
> > 
> 
> 
> just so i don't come across as a total idiot, i did understand that
> "?=" is a conditional assignment -- my question was whether it had
> immediate evaluation semantics like ":=" or delayed evaluation
> semantics like "=", and you appear to have answered that. thanks.
> 
> rday
> 
> -- 
> 
> ========================================================================
> Robert P. J. Day Ottawa, Ontario, CANADA
> http://crashcourse.ca
> 
> Twitter: http://twitter.com/rpjday
> LinkedIn: http://ca.linkedin.com/in/rpjday
> ========================================================================
> 
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core at lists.openembedded.org (mailto:Openembedded-core at lists.openembedded.org)
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
> 
> 


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openembedded.org/pipermail/openembedded-core/attachments/20120621/3bb32a9e/attachment-0002.html>