Visualize arbitrary tree in Racket using tree-layout

Question

How to visualise arbitrary tree?

for example: (define T1 \'(and (or x1 x2)(or x3 x4 x5)))

or one generated with:

(define fun         


        

Answer 1

I think improvements can be made to assefamaru's answer -

• Separate list traversal from individual node rendering
• Simplify case analysis of input
  1. If the input is null (base case), return empty tree, #f
  2. Otherwise (inductive) the input is not null. If the input is a list, Create a tree-layout of op and recursively apply draw to args
  3. Otherwise (inductive) the input is not null and the input is not a list. Create a tree-layout of atom a

Numbered lines above correspond to comments below -

(define (my-node a)
  (cc-superimpose
   (disk 30 #:color "white")
   (text (symbol->string a))))

(define (draw atom->pict a)
  (cond ((null? a) #f)                                 ;; 1
        ((list? a) (match a                            ;; 2
                     ((cons op args)
                      (apply tree-layout
                             #:pict (atom->pict op)
                             (map (curry draw atom->pict) args)))
                     (_ #f)))
        (else (tree-layout #:pict (atom->pict a)))))   ;; 3

(define my-tree
  '(or (if A1 (and A1 (not (if D1 (and A0 A0) (or A0 A0)))) (or A0 A0)) D0))

(naive-layered (draw my-node my-tree))

Answer 2

You can do something like this to visualize arbitrarily sized trees:

(require pict
         pict/tree-layout)

(define (draw tree)
  (define (viz tree)
    (cond
      ((null? tree) #f)
      ((not (pair? tree))
       (tree-layout #:pict (cc-superimpose
                            (disk 30 #:color "white")
                            (text (symbol->string tree)))))
      ((not (pair? (car tree)))
       (apply tree-layout (map viz (cdr tree))
              #:pict (cc-superimpose
                      (disk 30 #:color "white")
                      (text (symbol->string (car tree))))))))
  (if (null? tree)
      #f
      (naive-layered (viz tree))))

For example, using the lists you provided:

(define t1 '(and (or x1 x2) (or x3 x4 x5)))
(define t2 '(or (if A1 (and A1 (not (if D1 (and A0 A0) (or A0 A0)))) (or A0 A0)) D0))