\fill-line while respecting natural widths

[Mike Solomon]

Hey all

If I have

\markup \fill-line {
foooooooooooooo baaaar hi
}

The line will be filled irrespective of the widths of the elements, meaning
that the middle element will always be on the center of the page.

Is there a way to do this such that the space between elements is

(line_length - (elt_0_length + elt_1_length + … + el_tn_length)) / (n - 1)

Cheers,
MS