auto-complete/popup-el — pull request #40 by terranpro (2013-05-06 08:27:10+00:00)
Title: Generic filtering callback support for popup-isearch w/example filter by docstring

I've found the docstring search case useful for searching for function argument types, keywords like deprecated, async, callback, and even elisp defun keywords like &rest and &key.

I thought that rather than just add docstring, generic filtering functionality should be exposed.

I've submitted this pull request as a potential fix for issue #39

Example use of this patch w/auto-complete:

```
(defun ac-isearch-doc ()
(interactive)
(when (ac-menu-live-p)
(ac-cancel-show-menu-timer)
(ac-show-menu)
(if ac-use-quick-help
(let ((popup-menu-show-quick-help-function
(if (ac-quick-help-use-pos-tip-p)
'ac-pos-tip-show-quick-help
'popup-menu-show-quick-help)))
(popup-isearch ac-menu
:callback 'ac-isearch-callback
:help-delay ac-quick-help-delay
:filter 'popup-isearch-filter-list-by-doc))
(popup-isearch ac-menu
:callback 'ac-isearch-callback
:filter 'popup-isearch-filter-list-by-doc))))
```