search for: rplaca

...dern) Lisps, including Scheme== R has call-by-need, not call-by-object-value. R does not have macros. R objects are values, not pointers, so a<-1:10; b<-a; b[1]<-999; a[1] => 999. Similarly, functions cannot modify the contents of their arguments. There is no equivalent to set-car!/rplaca (not even pairlists and expressions). For example, r<-pairlist(1,2); r[[1]]<-r does not create a circular list. And in general there doesn't seem to be substructure sharing at the semantic level (though there may be in the implementation). R does not have multiple value return in the Li...