completion-ui.el question: my vimpulse-show-completion-menu function always gives me an empty menu

completion-ui.el question: my vimpulse-show-completion-menu function always gives me an empty menu

[Jason Spiro]

Hi all,

I am trying to get menu completion working for Alessandro Piras'
vimpulse.el, available on EmacsWiki.  (Menu completion is an
ultra-nice feature.  Instead of having to press M-/ over and over
until you get what you want, you get a drop-down menu listing the
completion options.  To see what menu completion looks like in Vim,
see http://en.wikibooks.org/wiki/Learning_the_vi_editor/Vim/Useful_things_for_programmers_to_know)

If you have Toby Cubitt's predictive completion from
http://www.dr-qubit.org/emacs.php installed (incidentally, it's a very
cool package), I would appreciate if you could run this code so you
can answer my question 1 below:

;; Begin code {{{

(require 'completion-ui)

;; Note: This code has an additional bug in addition to the problem I
;; am asking about in this mailing list message:
;; When called with a MAXNUM of nil, this func sometimes fails.  (Seems
;; to work the first time, then fail all times after, in such cases.
;; To fix, call with a normal MAXNUM.)
(defun vimpulse-try-hippie-expand-listed-functions (prefix &optional maxnum)
;  (interactive "*MString to expand:
;nMaximum number of expansions, or nil for unlimited: ")
  (setq expansions nil)
  (with-temp-buffer
    (insert-string prefix)
    (hippie-expand nil)
    (unless (string-equal (current-message) "No expansion found")
      (while (and
              (not (string-equal
                    (current-message)
                    "No further expansions found"))
              (if maxnum (not (= (length expansions) maxnum))))
        ;; Hippie-expand was designed to be run interactively.  If
        ;; this-command and last-command are equal, it assumes it's
        ;; being called as a "repeated use" (additional call without
        ;; moving the point) and searches for additional expansions
        ;; with the same prefix.  So, make this-command and
        ;; last-command equal.
        (setq this-command last-command)
        (hippie-expand nil)
        (add-to-list 'expansions (buffer-string))
        (buffer-string)
      ))
    expansions))

(defun vimpulse-show-completion-menu ()
  (interactive)
  (setq-default completion-function
'vimpulse-try-hippie-expand-listed-functions)
  (setq completion-function 'vimpulse-try-hippie-expand-listed-functions)
  ;; is this always necessary?  Am I even ever supposed to call it?
  (completion-setup-overlay 'prefix)
  (completion-show-menu))

;; }}} End code

1. Whenever I start typing a word then run
vimpulse-show-completion-menu I get an empty menu.  Why?  (Am I using
completion-show-menu wrong?  It errors on me if I don't call
completion-setup-overlay first, so I call it first.  Should I?  In
general, what is the proper way to use completion-show-menu?  It's not
perfectly documented.

2. Should menu completion really be part of vimpulse.el, or should I
try to get it into the hippie-expand source base?  Or, alternatively,
would someone like to take over maintainership of my attempt to get
menu completion working in Emacs?

Thanks in advance,
Jason

P.S. I am using GNU Emacs 22.0.50.1 (i486-pc-linux-gnu, GTK+ Version
2.10.3) of 2006-09-19 on rothera, modified by Debian.  That's 6 months
old.  I am using predictive 0.16.2; I downloaded it today.

-- 
Jason Spiro: computer consulting with a smile.
I also provide training and spyware removal services for homes and businesses.
Call or email for a FREE 5-minute consultation. Satisfaction guaranteed.
+1 (416) 781-5938 / Email: info@jspiro.com / MSN: jasonspiro@hotmail.com

Re: completion-ui.el question: my vimpulse-show-completion-menu function always gives me an empty menu

[Toby Cubitt]

Hi,

I'm not surprised it doesn't work, because you're using completion-UI in 
completely the wrong way. (Excusable, since documentation is currently 
fairly non-existent :-) Instead, set 'completion-function' to a function 
that returns a list of possible completions, and leave completion-UI to 
do its job.

Your comment 2. is along the right lines: menu completion shouldn't be 
implemented in the vimpulse code base, or indeed in the code base of any 
other completion package. It should indeed be in something like the 
hippie-expand package. But that's precisely what completion-UI is! All 
the hippie-expand features, plus tooltips, menu-completion, 
auto-completion, hotkey completion etc. etc. Completion-UI is supposed 
to supersede hippie-expand, at least for in-buffer completion. So using 
completion-UI and hippie-expand at the same time is unlikely to work 
very well.

As an Elisp coder, you're not supposed to invoke *any* completion 
interface explicitly, as you've tried to do. Deciding which combination 
of user-interfaces to use is the user's business, not the package 
writer's. Maybe some users want to use menu completion, but others 
prefer to see a list in the echo area, whilst still others just want a 
tooltip to popup after a delay, etc. etc. Completion-UI offloads those 
choices onto the user, which is where they should be.

I hope that makes things a bit clearer. I fully appreciate that using 
completion-UI will be confusing until it's properly documented, although 
the commentary at the beginning of completion-ui.el does tersely explain 
how it should be used. (Setting 'completion-function' really is all 
there is to it, I promise!)

Toby


Jason Spiro wrote:
> Hi all,
> 
> I am trying to get menu completion working for Alessandro Piras'
> vimpulse.el, available on EmacsWiki.  (Menu completion is an
> ultra-nice feature.  Instead of having to press M-/ over and over
> until you get what you want, you get a drop-down menu listing the
> completion options.  To see what menu completion looks like in Vim,
> see 
> http://en.wikibooks.org/wiki/Learning_the_vi_editor/Vim/Useful_things_for_programmers_to_know) 
> 
> 
> If you have Toby Cubitt's predictive completion from
> http://www.dr-qubit.org/emacs.php installed (incidentally, it's a very
> cool package), I would appreciate if you could run this code so you
> can answer my question 1 below:
> 
> ;; Begin code {{{
> 
> (require 'completion-ui)
> 
> ;; Note: This code has an additional bug in addition to the problem I
> ;; am asking about in this mailing list message:
> ;; When called with a MAXNUM of nil, this func sometimes fails.  (Seems
> ;; to work the first time, then fail all times after, in such cases.
> ;; To fix, call with a normal MAXNUM.)
> (defun vimpulse-try-hippie-expand-listed-functions (prefix &optional 
> maxnum)
> ;  (interactive "*MString to expand:
> ;nMaximum number of expansions, or nil for unlimited: ")
>  (setq expansions nil)
>  (with-temp-buffer
>    (insert-string prefix)
>    (hippie-expand nil)
>    (unless (string-equal (current-message) "No expansion found")
>      (while (and
>              (not (string-equal
>                    (current-message)
>                    "No further expansions found"))
>              (if maxnum (not (= (length expansions) maxnum))))
>        ;; Hippie-expand was designed to be run interactively.  If
>        ;; this-command and last-command are equal, it assumes it's
>        ;; being called as a "repeated use" (additional call without
>        ;; moving the point) and searches for additional expansions
>        ;; with the same prefix.  So, make this-command and
>        ;; last-command equal.
>        (setq this-command last-command)
>        (hippie-expand nil)
>        (add-to-list 'expansions (buffer-string))
>        (buffer-string)
>      ))
>    expansions))
> 
> (defun vimpulse-show-completion-menu ()
>  (interactive)
>  (setq-default completion-function
> 'vimpulse-try-hippie-expand-listed-functions)
>  (setq completion-function 'vimpulse-try-hippie-expand-listed-functions)
>  ;; is this always necessary?  Am I even ever supposed to call it?
>  (completion-setup-overlay 'prefix)
>  (completion-show-menu))
> 
> ;; }}} End code
> 
> 1. Whenever I start typing a word then run
> vimpulse-show-completion-menu I get an empty menu.  Why?  (Am I using
> completion-show-menu wrong?  It errors on me if I don't call
> completion-setup-overlay first, so I call it first.  Should I?  In
> general, what is the proper way to use completion-show-menu?  It's not
> perfectly documented.
> 
> 2. Should menu completion really be part of vimpulse.el, or should I
> try to get it into the hippie-expand source base?  Or, alternatively,
> would someone like to take over maintainership of my attempt to get
> menu completion working in Emacs?
> 
> Thanks in advance,
> Jason
> 
> P.S. I am using GNU Emacs 22.0.50.1 (i486-pc-linux-gnu, GTK+ Version
> 2.10.3) of 2006-09-19 on rothera, modified by Debian.  That's 6 months
> old.  I am using predictive 0.16.2; I downloaded it today.
> 

Re: completion-ui.el question: my vimpulse-show-completion-menu function always gives me an empty menu

[Jason Spiro]

Hi Toby,

2007/3/14, Toby Cubitt <t.s.cubitt.98-dated-1174279006.800fd7@cantab.net> wrote:
> I'm not surprised it doesn't work, because you're using completion-UI in
> completely the wrong way. (Excusable, since documentation is currently
> fairly non-existent :-) Instead, set 'completion-function' to a function
> that returns a list of possible completions, and leave completion-UI to
> do its job.
>
Will try it - thanks for the explanation.

> Your comment 2. is along the right lines: menu completion shouldn't be
> implemented in the vimpulse code base, or indeed in the code base of any
> other completion package. It should indeed be in something like the
> hippie-expand package. But that's precisely what completion-UI is! All
> the hippie-expand features, plus tooltips, menu-completion,
> auto-completion, hotkey completion etc. etc. Completion-UI is supposed
> to supersede hippie-expand, at least for in-buffer completion. So using
> completion-UI and hippie-expand at the same time is unlikely to work
> very well.
>
I decided on hippie-expand because it can complete:

- words (like dabbrev does)
- filenames
- entire buffer lines.

and more.  I am trying to emulate Vim's completion behavior, and Vim
can complete all those things and more.  Unfortunately it can't
complete multiple-word sequences like dabbrev can when you press M-/
SPC M-/ SPC M-/ but I hope someone else or I will add that later.

> As an Elisp coder, you're not supposed to invoke *any* completion
> interface explicitly, as you've tried to do. Deciding which combination
> of user-interfaces to use is the user's business, not the package
> writer's. Maybe some users want to use menu completion, but others
> prefer to see a list in the echo area, whilst still others just want a
> tooltip to popup after a delay, etc. etc. Completion-UI offloads those
> choices onto the user, which is where they should be.
>
I want Vimpulse to emulate Vim's completion behavior: when you press
C-n, C-p, or any of the other completion keys in Insert mode: it shows
a menu.  Is there a way to programmatically change a Customize
variable's default so that my change will take effect if and only if
the user does not customize that variable themselves?

> I hope that makes things a bit clearer. I fully appreciate that using
> completion-UI will be confusing until it's properly documented, although
> the commentary at the beginning of completion-ui.el does tersely explain
> how it should be used. (Setting 'completion-function' really is all
> there is to it, I promise!)
>
I eagerly await that future day when it'll be better documented then :-)

Till then, do you know of any code examples that call completion-ui
that I could look at?

Cheers,
Jason

-- 
Jason Spiro: computer consulting with a smile.
I provide software development and training services to clients worldwide.
Contact me for a FREE consultation. Satisfaction guaranteed.
+1 (416) 781-5938 / Email: info@jspiro.com / MSN: jasonspiro@hotmail.com

Re: completion-ui.el question: my vimpulse-show-completion-menu function always gives me an empty menu

[Jason Spiro]

Hi list, hello Toby,

As you may know, I am working on vimpulse[1] which extends viper-mode
to emulate the most useful Vim keys in Emacs.  I am hoping to add C-n
and C-p completion to vimpulse, and I am wondering how to do so.

I am hoping to use hippie-expand because it can complete:

- words,
- filenames, and
- entire buffer lines

among other things.[2]  Dabbrev seems to basically only complete
words.  I am trying to emulate Vim's completion behavior, and Vim can
complete all those things and more.[3]

> As an Elisp coder, you're not supposed to invoke *any* completion
> interface explicitly, as you've tried to do. Deciding which combination
> of user-interfaces to use is the user's business, not the package
> writer's. Maybe some users want to use menu completion, but others
> prefer to see a list in the echo area, whilst still others just want a
> tooltip to popup after a delay, etc. etc. Completion-UI offloads those
> choices onto the user, which is where they should be.

OK.  I will tell vimpulse users they should set certain Completion-UI
settings themselves to get something closer to Vim completion.  But
meanwhile, I still have a question about the code I am writing myself
for testing purposes.

;; Begin code {{{

(require 'completion-ui)

;; Note: This code has an additional bug in addition to the problem I
;; am asking about in this mailing list message:
;; When called with a MAXNUM of nil, this func sometimes fails.  (Seems
;; to work the first time, then fail all times after, in such cases.
;; To fix, call with a normal MAXNUM.)
(defun vimpulse-try-hippie-expand-listed-functions (prefix &optional maxnum)
;  (interactive "*MString to expand:
;nMaximum number of expansions, or nil for unlimited: ")
 (setq expansions nil)
 (with-temp-buffer
   (insert-string prefix)
   (hippie-expand nil)
   (unless (string-equal (current-message) "No expansion found")
     (while (and
             (not (string-equal
                   (current-message)
                   "No further expansions found"))
             (if maxnum (not (= (length expansions) maxnum))))
       ;; Hippie-expand was designed to be run interactively.  If
       ;; this-command and last-command are equal, it assumes it's
       ;; being called as a "repeated use" (additional call without
       ;; moving the point) and searches for additional expansions
       ;; with the same prefix.  So, make this-command and
       ;; last-command equal.
       (setq this-command last-command)
       (hippie-expand nil)
       (add-to-list 'expansions (buffer-string))
       (buffer-string)
     ))
   expansions))

(defun jason-problem-demo ()
 (interactive)
 (setq-default completion-function
'vimpulse-try-hippie-expand-listed-functions)
 (setq completion-function 'vimpulse-try-hippie-expand-listed-functions)
 ;; is this always necessary?  Am I even ever supposed to call it?
 (completion-setup-overlay 'prefix)
 (completion-show-menu))

;; }}} End code

Whenever I start typing a word then run
M-x jason-problem-demo I get an empty menu.  Why?

Am I using
completion-show-menu wrong?  It errors on me if I don't call
completion-setup-overlay first, so I call it first.  Should I?

Cheers,
Jason[5]

[1] http://www.emacswiki.org/cgi-bin/wiki/vimpulse.el

[2] Unfortunately hippie-expand can't complete multiple-word sequences
like dabbrev can when you press M-/ SPC M-/ SPC M-/.  Vim can do it:
just press CTRL-X CTRL-P repeatedly.  But I hope I'll eventually fix
that.

Then again, maybe I'll never have time to make that change to
hippie-expand.  So maybe I should have Completion-UI call
dabbrev-expand instead.

[3] e.g. CTRL-X CTRL-T for thesaurus completion, or many other[4] things.

[4] http://ianua.initd.org/vimit/vim63/html/insert.html#ins-completion

[5] P.S. You may want to mention in the completion-ui documentation at
the top of the file that
http://www.emacswiki.org/cgi-bin/wiki/CompletionUI#toc2 has examples
of how to use completion-ui with dabbrev and etags.  If I knew that
info, it would have saved me time. :-)

-- 
Jason Spiro: computer consulting with a smile.
I provide software development and training services to clients worldwide.
Contact me for a FREE consultation. Satisfaction guaranteed.
+1 (416) 781-5938 / Email: info@jspiro.com / MSN: jasonspiro@hotmail.com