🚀 go-pugleaf

In article <4l1id6$pva@solutions.solon.com>, 
schwarz@mips.complang.tuwien.ac.at says...
> A difficulty I see with an extendible printf is devising a mechanism
> so that unrelated modules can cooperate on extensions.  

[ ... ] 

I've thought of this - it might be nice to include a function to attempt to 
allocate an unused character, though this of course prevents you from using 
literals for the conversion strings, which is certainly less convenient.  I 
believe Peter also mentioned a flag to find out whether a flag is presently in 
use.  However, in the case of a multithreaded system, it might be better to 
(perhaps additionally) have a flag to use set the format for a particular 
character, but fail if it's already in use.  (This should make checking 
whether a flag is in use, and allocating it if not atomic, preventing problems 
with race conditions that can arise when the two are separate operations.)
    Later,
    Jerry.