(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
	      (list 
	       (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)))
	      (list ;; 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 nodedist nodedep)
  (letrec (
	   ;; nodeinit -> to init all node values on -1
	   (nodeinit  
	    (lambda (ndlst) 
	      (if (null? ndlst)
		  '()
		  (begin
		    (define (caar ndlst) -1)
		    (nodeinit (cdr ndlst))))))
	   ;; nlist -> list of nodes
	   (nlist (crnode nodedist)) 
	   ;; crnode -> node builder
	   (crnode (lambda (x) 
		     (if (null? x)
			 '()
			 (cons (caar x)
			       (crnode (cdr x))))))
	   ;; crndtaken -> find if nodes have already ben set builder
	   (crndtaken (lambda (lst)
			(and (not (= (eval (caar lst)) -1)) (crndtaken (cdr lst)))))
	   ;; nodenottaken? -> find if there are unset nodes
	   (nodenottaken? (crndtaken nodedist))
	   (compute (lambda (ndlst)
		      (if (not (null? ndlst))
			  (begin
			    (
    (begin
      (nodeinit nodedist)
      (while (nodenottaken?)
	     (compute nodelist)))