image-files = path mask + result ->
  i = name @fp ->
    has-image-ext -a = name ->
      [ name, '.png' | name, '.jpg' | name, '.gif' ]
    ;

    - fp name [ name->has-image-ext && file-size name > 0 ]
  ;

  - files path mask ( file-name -> - i file-name ( n -> attach result n ) )
;


