(use srfi-1)
(use srfi-27)

(define-syntax while
  (syntax-rules ()
    ((while condition things ... )
     (do () ((not condition)) things ...))))

;; (define x 0)
;; (while (< x 10) (set! x (+ x 1)) (display x))

(define obra
  (graph
   ;; nodes and distributions
   `((T1 ,(uniform 32 48))
     (T2 ,(uniform 40 60))
     (T3 ,(uniform 15 25))
     (T4 ,(uniform 10 15))
     (T5 ,(uniform 10 15))
     (T6 ,(uniform 6 10))
     (T7 ,(uniform 18 24))
     (T8 ,(uniform 4 8)))
   ;; dependencies
   '((T2 . T1)
     (T3 . T1) (T3 . T2)
     (T4 . T2)
     (T5 . T2) (T5 . T3)
     (T6 . T2)
     (T7 . T2) (T7 . T4) (T7 . T5)
     (T8 . T4) (T8 . T5) (T8 . T6) (T8 . T7))))

(define (uniform min max)
  (+ min (* (- max min) (random-real))))

(define (graph nodes-with-distributions node-dependencies)
  ;; crnd-taken -> find if nodes have already ben set builder
  (define (crnd-taken lst)
    (every (lambda (node)
             (not (= (eval (car node)) -1)))
           lst))
  ;; node-not-taken? -> find if there are unset nodes
  (define (node-not-taken?) (crnd-taken nodes-with-distributions))
  (define (compute ndlst)
    (if (not (null? ndlst))
        (begin
          (...))
        ...))
  ;; nlist -> list of nodes
  (define nlist (map car node-with-distributions))
  ;; init all node values on -1
  (for-each (lambda (node)
              ;; hm, probably not what you want
              (set-car! node -1))
            nodes-with-distributions)
  (while (node-not-taken?)
         (compute nodes-with-distributions)))