Re: HELP: One Bindkey for Two Different Commands

[Edward <edward.dodge@gmail.com>]

On Nov 21, 2:33 am, "Drew Adams" <drew.ad...@oracle.com> wrote:
> > >> Why waste two bindkeys on two similar commands when you can simply
> > >> write a function to choose the between commands based on context?
>
> > >> Unfortunately,  this very simple idea doesn't seem to work for me.
> > >> Here's what I have in my .emacs so far:
>
> > >> (defun ya-ya ()
> > >>   (if (cdr (window-list))
> > >>       'other-window
> > >>     'switch-to-buffer))
>
> > >> (global-set-key "\M-o" (ya-ya))
> > >> Any ideas how this might be accomplished?
>
> > > To turn a function into a command, add an `interactive' spec.
>
> > > The functions other-window and switch-to-buffer require arguments.
>
> > Your point being?  other-window and switch-to-buffer both have an
> > interactive spec.
>
> Just trying to help.
>
> To be more clear: You need to call function `other-window' or
> `switch-to-buffer', not just return the symbol. And calling them means
> providing their required arguments - use either (call-interactively
> 'other-window) or (other-window <some-window-number>).
>
> > > The second argument to global-set-key is a command, not a list such as
> > > you have supplied.
>
> > He does not supply a list.  He supplies a command.
>
> Sorry, I misread '(ya-ya) instead of (ya-ya).
>
> > The problem merely is that he makes his choice of command at
> > the time of global-set-key, not at keypress time.
>
> To be more helpful: You need to pass the symbol `ya-ya', instead of calling
> the function `ya-ya': (global-set-key "\M-o" 'ya-ya). A key is bound to a
> command (or its symbol), not to the result of calling the command.
>
> This is the opposite mistake from that made with `other-window' (returning
> the symbol instead of calling the function). As David suggested, you called
> `ya-ya' at key-binding time, so one of the symbols it returns at that time,
> not `ya-ya', gets bound to `M-o'.- Hide quoted text -
>
> - Show quoted text -

Drew & David,

Thank you so much for your help!  I wish Lisp had been my first
language,  because then it would have been easier to remember how
simple and powerful command syntax can be.  Althouth I've learned a
lot about Lisp in the past year,  I'm still used to languages where
the syntax is more idiosyncratic and arbitrary.  Because of this I
find myself making the sort of mistakes you have mentioned.

Anyway,  here is the new code that works for anyone who is interested:

(defun ya-ya ()
  (interactive) ; new
  (if (cdr (window-list))
      (other-window 1)  ; command with argument
    (call-interactively 'switch-to-buffer))) ; command called
interactively, argument to be passed at that time

(global-set-key "\M-o" 'ya-ya) ; command symbol passed, instead of the
last symbol returned by the function!


Your guidance has helped me quite a bit here.  I plan on using this
same technique to contextualize my keybindings for more commands and
editing situations.

Thanks again,

Edward