Important: These functions are for expert R programmers only. You should only use them if you feel comfortable manipulating low level R data structures at the C level. We export them at the R level in order to make it easy to prototype C code. They don't perform any type checking and can crash R very easily (try to take the CAR of an integer vector --- save any important objects beforehand!).
Usage
new_node(car, cdr = NULL)
node_car(x)
node_cdr(x)
node_caar(x)
node_cadr(x)
node_cdar(x)
node_cddr(x)
node_poke_car(x, newcar)
node_poke_cdr(x, newcdr)
node_poke_caar(x, newcar)
node_poke_cadr(x, newcar)
node_poke_cdar(x, newcdr)
node_poke_cddr(x, newcdr)
node_tag(x)
node_poke_tag(x, newtag)Arguments
- car, newcar, cdr, newcdr
The new CAR or CDR for the node. These can be any R objects.
- x
A language or pairlist node. Note that these functions are barebones and do not perform any type checking.
- newtag
The new tag for the node. This should be a symbol.
Value
Setters like node_poke_car() invisibly return x modified
in place. Getters return the requested node component.
See also
duplicate() for creating copy-safe objects and
base::pairlist() for an easier way of creating a linked list of
nodes.