Method: Cons#copy_tree

Defined in:

lib/cons.rb

#copy_tree ⇒ Object Also known as: tree_copy

Creates a copy of a tree of conses.

If tree is not a cons, it is returned; otherwise, the result is a new cons of the results of calling copy-tree on the car and cdr of tree. In other words, all conses in the tree represented by tree are copied recursively, stopping only when non-conses are encountered.

copy-tree does not preserve circularities and the sharing of substructure.

Cf. <clhs.lisp.se/Body/f_cp_tre.htm>

# File 'lib/cons.rb', line 241

def copy_tree
  new_car = if car.kind_of? Cons
              car.copy_tree
            else
              car
            end
  new_cdr = if cdr.kind_of? Cons
              cdr.copy_tree
            else
              cdr
            end
  Cons[new_car,new_cdr]
end