Re: ElDoc: adding optional support to display messages in header-line instead of the echo area

[Tassilo Horn <tassilo@member.fsf.org>]

Geralt <usr.gentoo@googlemail.com> writes:

Hi!

>> You probably mean something like
>>
>>      (cond
>>       (eldoc-last-message
>>        (if eldoc-display-in-header-line
>>            (setq header-line-format eldoc-last-message)
>>          (message "%s" eldoc-last-message)))
>>       (omessage (message nil)))))
>>
>> here ;-)
>
> can you explain why?

Cause the variable `omessage' is bound to `eldoc-last-message' in the
beginning of the function, and it serves as condition in the `cond'.
After the `let', `eldoc-last-message' set to the new eldoc string.  If
there's non created, cause point is not on a function/var, then the new
value is nil.  If that is the case, but the old message (omessage) is
non-nil, the echo area will be cleared.

> I put the omessage into the ELSE block because somebody on emacs-help
> suggested it and it made sense to me at that time.

Yep, been there, didn't check accurately, didn't object.  But Martin is
right. :-)

Bye,
Tassilo