Rdo_insert_element(rdo, val, pos)
val
, typically an integer
but may be anything accepted by the operator "[[".
val
is inserted at position pos
, between the elements at
positions pos-1
and pos
. If pos
is equal to 1,
val
is prepended to rdo
. If pos
is missing or
equal to the length of rdo
, val
is appended to
rdo
. todo: allow vector pos
to insert deeper into the object.
todo: character pos
to insert at a position specified by "tag" for example?
todo: more guarded copying of attributes?