limit stream -- convergent approximation for data

so many representation for a single entity
- url- path
- file handler
- file metadata
- file header

on a graphical side
- icon
- named cell
- preview

somehow they're ordered, like a lazy stream whose data is the limit

url | path -> r : lim stream
(r) -> file handler , r
   (r) -> file metadata , r
      (r) -> file header , r
         (r) -> file byte stream, ()