To install this package, run in Emacs:
M-x package-install RET eldoc-eval RET
This package enables eldoc support when minibuffer is in use. Eldoc info is shown by default in mode-line, but you can have eldoc info somewhere else by setting `eldoc-in-minibuffer-show-fn' to another function (e.g `tooltip-show'). By default with this package `M-:' will use `pp-eval-expression' instead of `eval-expression'; you can change that by setting `eldoc-eval-preferred-function'. It also provides a convenient macro to enable eldoc support in your own functions using minibuffer or in your defadvices, that is `with-eldoc-in-minibuffer'. Users of own minibuffer frame will have to set `eldoc-in-minibuffer-own-frame-p' to non-nil. You can turn On/Off eldoc support in minibuffer any time with `eldoc-in-minibuffer-mode'.