[Nickle] printf/scanf for rationals?

[Barton C Massey]

There appears to be no current way to printf() a rational so
that it can be read back in accurately with scanf().  Am I
mistaken?  If not, is this a bug?  Should there be a scanf()
format string for e.g. (1/3)?  For 0.{3}?  Both?

    Bart