Thank you Ric and Robert. A trie is more like a nested hash table than a mere tree. It is essential in a trie (as it is in a hash table) that you have O(m) time lookup. That is, a trie is more than a hierarchical boxing of values or a vector presentation of a trees relationships.
From your links Ric, I dismay somewhat at Dan Bron's conclusion because it is exactly what the sceptic in me was thinking: "If you're already an array-thinker, and you're familiar with J, and still conclude your program (primarily) needs to manipulate trees, perhaps you should write it in another language. One of J's primary advantages is that it makes (array) programming easy. If its notation is inapplicable to your problem (more or less), there is not much reason left to use it." Emir ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
