This isn't meant to be a good programming mechanism, it's meant to be an illustration of how to use the macro system.
But also, if you're processing non-linear data, you're going to want to do with a recursive function anyway. E.g., when dealing with a tree. Code below; can't seem to get multi-line code-formatting so it looks hideous:
But also, if you're processing non-linear data, you're going to want to do with a recursive function anyway. E.g., when dealing with a tree. Code below; can't seem to get multi-line code-formatting so it looks hideous:
#lang racket
(require "anon-rec.rkt") (require rackunit)
(struct mt ()) (struct node (v l r))
(define sum-tree (lam/anon (t) (cond [(mt? t) 0] [(node? t) (+ (node-v t) ($MyInvocation (node-l t)) ($MyInvocation (node-r t)))])))
(define t (node 5 (node 3 (mt) (mt)) (node 7 (node 9 (mt) (mt)) (mt))))
(check-equal? (sum-tree t) 24)