(define (find-particles arr particle-type)
  ; an iterating search that accumulates its results by recursion (?)
  (define (find f #!optional (iter-state '(0 0)) (accumulator '())) ; f: state -> (state result) is the searcher function
    (match-let ([(nextstate result) (f iter-state)])
      (if (not (null? result))
          (find f next-state (cons result acc))
          (accumulator)) ))

  (define (find-next arr iter-state particle-type)
    (define w (dim-size arr 0))
    (define h (dim-size arr 1))
    (match-let ([(i . j) iter-state])
      (do-for i (i w) ; use recursive style loop because this lib doesnt support a break construct
              (do-for j (j h)
                      
                      )) ))
  
  (define searchf
    (lambda(iter-state)
      (find-next arr iter-state particle-type)))

  (find searchf)
  )