R help - Jan 2003 - difference between "external pointer" and "weak reference"

Dear R-help,

Could you tell me where can I read more about the difference between
"external pointer"(EXTPTRSXP) and "weak
reference"(WEAKREFSXP) in R and what
were they intended for? 

Regards,

Krassimir Vanguelov 


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http://developer.r-project.org has the background papers.

On Fri, 17 Jan 2003, Vanguelov, Krassimir wrote:
> Could you tell me where can I read more about the difference between
> "external pointer"(EXTPTRSXP) and "weak
reference"(WEAKREFSXP) in R and what
> were they intended for? 
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595