A structural string for a tree: "*" for a leaf, "NULL" for an empty
node, "list(...)" for list nodes, and for an object of a class registered
with register_tree_node() whatever its repr makes of it. A named list is
tagged "list<named>(...)", so that a list whose names are all empty is
told apart from an unnamed one. The string is canonical – trees that are
not tree_equal() print differently – as far as the reprs of their
classes are, and except for trees built under two registrations of a class,
which may print alike.
Arguments
- tree
(
RTree)
A tree as returned bybuild_tree().
Examples
tree_repr(build_tree(list(a = 1, b = list(2, NULL))))
#> [1] "list<named>(a = *, b = list(*, NULL))"