You are confusing 'length' wih the number of characters in an element.
At least the present documentation is not incorrect!
> length("")
[1] 1
I think we normally say a string is non-empty (some say non-blank, but
others including me think " " is blank).
On Wed, 16 Aug 2006, Gregor Gorjanc wrot
Hello!
It seems that prompt and continue argument of options() must be at least
of length one i.e.
> options(prompt="")
Error in options(...) : prompt parameter invalid
> options(prompt=" ")
# bla, bla, ...
> options(prompt="> ")
> # bla, bla, ...
> options(continue="")
Error in options(...) :
