about the new 'flatten' function: For the case of string arrays I think
it would be good to have some choice about the separator. Currently a
newline (\n) is inserted after each string, which is reasonable.
However, there's an unused argument ('vcat') which could be used to
choose for example a blank (" ") instead. An alternative would be to
introduce another optional argument where the user could specify the
string for joining (or separating) the input strings.
This would be useful if the input array actually holds textual
representations of numbers, which can then be processed with sscanf.
Both alternatives would be backwards compatible, but flatten is so new
that that's not very important I guess.