table builtins: get_calls, get_returns, abolish_all_tables, ...
trie_assert, trie_retract (or maybe in section on large files, or maybe in a separate chapter on indexing.)
Do example to extract parses from a table created by recognition of a string in a CF grammar. (How to do, maybe interpreter.)
As examples, how about suspend / resume (which Rui has working at least partly) and the cursors / server example?