in reply to Learning Emacs

I am searching an elisp module I once used. For professional reason I had to use vi and lost track about the said elisp module. It does a special form of autocompletion best explained by example: M-X q-r-r TAB would give M-X query-replace-regexp
Instead of completing on the whole word, it breaks it on the dash and try to complete all the parts so that when reasembled it makes the name of a command. This should not be too difficult to write for someone who is proficient in elisp. I am not. And probably this module is out somewhere on the net. But Where?

-- stefp