"in clojure"

1- Write (preorder-traversal visitor tree) which evaluates the procedure visitor with each node of tree, in pre-order order (visit the node, traverse the left subtree, then traverse the right subtree). Write code that uses preorder-traversal to print an expression in prefix notation given its parse tree. Your visitor should add parentheses so your output looks like LISP expressions, if possible.

2- Write (postorder-traversal visitor tree) which evaluates the procedure visitor with each node of the tree, in post-order (traverse the left subtree, traverse the right subtree then visit the node itself). Write code that uses postorder-traversal to print the postfix expression given its parse tree. For example, the expression (5 + 3) * 2. Your output may not contain parentheses (there is no need for them in postfix).