Highlight hidden text?

[kenahoo]

I just discovered this package, it's awesome.

Might there be a way to visually indicate that a chunk of text has been hidden, e.g. changing its background color to yellow? That would help me quickly understand the structure of a file, by knowing there's more there than meets the eye. Particularly in R, where ... is a syntactically valid identifier, I often get things like this:

myfunc <- function(files, ...) {...}