Hi, I have a huge list. Normally it is sorted, but I want to be able to add elements to it without having to use any special interfaces and then sort it on demand. My idea is to use something like weak references combined with attributes. Consider:
# Initialization. l = as.list(1:10) # Note that it is sorted. attr(l, 'sorted') = weakref(l) # Modify the list. l = append(l, 1:3) # Check if the list is still sorted. (I use identical here, but it # probably too heavy weight: I just need to compare the addresses.) if (! identical(l, attr(l, 'sorted'))) { l = sort(unlist(l)) attr(l, 'sorted') = weakref(l) } # Do operation that requires sorted list. ... This is obviously a toy example. I'm not actually sorting integers and I may use a matrix instead of a list. I've read: http://www.hep.by/gnu/r-patched/r-exts/R-exts_122.html http://homepage.stat.uiowa.edu/~luke/R/references/weakfinex.html As far as I can tell, weakrefs are only available via the C API. Is there a way to do what I want in R without resorting to C code? Is what I want to do better achieved using something other than weakrefs? Thanks! :) Neal ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.