I came here to basically say the same thing ... if Knuth weren't demonstrating Literate Programming (LP), he would have used a library version of the Trie function that took up most of those eight pages. At that point, who cares whether those six pages were done in (LP) or not ... it might be easier to maintain in the long-term but either way it's code you don't have to write. If he was finding the Levenshtein distance as with this post, maybe his LP system could use the Perl library too?
