A value boxed with done()
signals to its caller that it
should stop iterating. Use it to shortcircuit a loop.
done(x) is_done_box(x, empty = NULL)
x | For |
---|---|
empty | Whether the box is empty. If |
A boxed value.
done(3) #> <done> #> [1] 3 x <- done(3) is_done_box(x) #> [1] TRUE