Here is a short but complete program in Berkeley Logo:
to choices :menu [:sofar []] if emptyp :menu [print :sofar stop] foreach first :menu [(choices butfirst :menu sentence :sofar ?)] end
And here's how you use it. You type
choices [[small medium large]
[vanilla [ultra chocolate] lychee [rum raisin] ginger]
[cone cup]]
and Logo replies
small vanilla cone small vanilla cup small ultra chocolate cone small ultra chocolate cup small lychee cone small lychee cup small rum raisin cone small rum raisin cup small ginger cone small ginger cup medium vanilla cone medium vanilla cup medium ultra chocolate cone medium ultra chocolate cup medium lychee cone medium lychee cup medium rum raisin cone medium rum raisin cup medium ginger cone medium ginger cup large vanilla cone large vanilla cup large ultra chocolate cone large ultra chocolate cup large lychee cone large lychee cup large rum raisin cone large rum raisin cup large ginger cone large ginger cup
The program doesn't have anything about the size of the menu built in. You can use any number of categories, and any number of possibilities in each category. Let's see you do that in four lines of Java!
www.cs.berkeley.edu/~bh