Questions about LISP and Python.

[Terry Reedy]

On 12/7/2011 5:14 AM, Andrea Crotti wrote:
> On 12/06/2011 04:36 AM, Xah Lee wrote:
>> i don't like python, and i prefer emacs lisp. The primary reason is
>> that python is not functional, especially with python 3. The python
>> community is full of fanatics with their drivels. In that respect,
>> it's not unlike Common Lisp community and Scheme lisp community.
>>
>
> I love emacs and I love python, but saying that elisp is a better language
> than python and more functional is plain ridiculous.
> Elisp is great to extend Emacs, but with dynamic scoping and side effects
> used everywhere should not even be considered between the functional
> languages, at least for how it's mainly used.
>
> This is a typical usage taken from simple.el
> (defun pop-global-mark ()
> "Pop off global mark ring and jump to the top location."
> (interactive)
> ;; Pop entries which refer to non-existent buffers.
> (while (and global-mark-ring (not (marker-buffer (car global-mark-ring))))
> (setq global-mark-ring (cdr global-mark-ring)))
> (or global-mark-ring
> (error "No global mark set"))
> (let* ((marker (car global-mark-ring))
> (buffer (marker-buffer marker))
> (position (marker-position marker)))
> (setq global-mark-ring (nconc (cdr global-mark-ring)
> (list (car global-mark-ring))))
> (set-buffer buffer)
> (or (and (>= position (point-min))
> (<= position (point-max)))
> (if widen-automatically
> (widen)
> (error "Global mark position is outside accessible part of buffer")))
> (goto-char position)
> (switch-to-buffer buffer)))
>
> Which means more or elss pop a mark from the mark ring, get the current
> buffer/position,
> then set the buffer, widen if necessary, go to some position and switch
> to that buffer.
>
> Nothing wrong with it, but basically it messes around with global state,
> as most elisp functions
> do.
>
> And how python 3 would be less functional?

It does not pretend that surrounding statements with parentheses turns 
them into expressions.
;-)

-- 
Terry Jan Reedy