ido-mode
ido-mode is an interactive autoloaded compiled Lisp function in `ido.el
'.
(ido-mode &optional ARG)
Toggle Ido mode on or off.
With ARG, turn Ido mode on if arg is positive, off otherwise.
Turning on Ido mode will remap (via a minor-mode keymap) the default
keybindings for the `find-file' and `switch-to-buffer' families of
commands to the Ido versions of these functions.
However, if ARG arg equals 'files, remap only commands for files, or
if it equals 'buffers, remap only commands for buffer switching.
This function also adds a hook to the minibuffer.