Re: Why is Elisp slow?

[Ergus]

On Tue, May 07, 2019 at 10:16:42PM +0900, ????????? wrote:

Yes, it is not straight forward, but that's what makes it more
interesting (and useful).

I still think that provide a plugin for SBCL is the best to do it native
and efficient, but I have zero knowledge about the SBCL infrastructure
for that. But the idea of adding it some C bindings is not
crazy. Specially because all the functions have the same signature. We
just need some documentation about the internal data structure
representations in SBCL.

> Ahh??? I now understood what???s the problem. :-(
>
> > 2019. 5. 7. ?????? 10:04, Stefan Monnier <monnier@IRO.UMontreal.CA> ??????:
> >
> > > > Similarly, you'll need to rewrite all the functions/macros like CONSP,
> > > > SYMBOLP, FIXNUMP, XCAR, XCDR, make_fixnum, ...  Performance of those
> > > > is important.
> > >
> > > Why would you not use the default CL???s defun, car, cdr, symbol-p,
> > > cons-p, etc, etc?
> >
> > I'm talking the work needed to adapt Emacs's C code, e.g:
> >
> >    DEFUN ("get-buffer-window", Fget_buffer_window, Sget_buffer_window, 0, 2, 0,
> >           doc: /* Return a window currently displaying BUFFER-OR-NAME, or nil 
> > if none.
> >    BUFFER-OR-NAME may be a buffer or a buffer name and defaults to
> >    the current buffer.
> >
> >    The optional argument ALL-FRAMES specifies the frames to consider:
> >
> >    - t means consider all windows on all existing frames.
> >
> >    - `visible' means consider all windows on all visible frames.
> >
> >    - 0 (the number zero) means consider all windows on all visible
> >        and iconified frames.
> >
> >    - A frame means consider all windows on that frame only.
> >
> >    Any other value of ALL-FRAMES means consider all windows on the
> >    selected frame and no others.  */)
> >         (Lisp_Object buffer_or_name, Lisp_Object all_frames)
> >    {
> >      Lisp_Object buffer;
> >
> >      if (NILP (buffer_or_name))
> >        buffer = Fcurrent_buffer ();
> >      else
> >        buffer = Fget_buffer (buffer_or_name);
> >
> >      if (BUFFERP (buffer))
> >        return window_loop (GET_BUFFER_WINDOW, buffer, true, all_frames);
> >      else
> >        return Qnil;
> >    }
> >
> >
> > -- Stefan