completion-search-peek

completion-search-peek is a compiled Lisp function in `completion.el'.

(completion-search-peek USE-CDABBREV)

Return the next completion entry without actually moving the pointers.
Calling this again or calling `completion-search-next' results in the same
string being returned. Depends on `case-fold-search'.
If there are no more entries, try cdabbrev and then return only a string.