[Info-vax] BASIC (and Horizon)

[Lawrence D'Oliveiro]

On Fri, 2 Feb 2024 07:56:33 -0500, Arne Vajhøj wrote:

> On 2/1/2024 11:51 PM, Lawrence D'Oliveiro wrote:
>> On Thu, 1 Feb 2024 22:44:56 -0500, Arne Vajhøj wrote:
>>> To quote from Linux kernel coding style doc:
>>>
>>> <quote>
>>> Now, some people will claim that having 8-character indentations makes
>>> the code move too far to the right, and makes it hard to read on a
>>> 80-character terminal screen. The answer to that is that if you need
>>> more than 3 levels of indentation, you’re screwed anyway, and should
>>> fix your program.
>> 
>> I think this is a load of nonsense.
> 
> Apparently Linus doesn't think so.

I know he doesn’t.

> And while few may have worded is this blunt, then it is generally
> accepted that deep nesting is a code smell and should be refactored and
> code moved out to functions/methods.

I do deep nesting all the time. This one goes 8 levels deep.

(defun prev_less_indent (count)
    "moves to the last prior line with a lesser indentation level."
    (interactive "p")
    (loop break
        (back-to-indentation)
        (let
            (
                (indent_end (point))
                indent_amt
                line_start
            )
            (beginning-of-line)
            (cond
                ((> indent_end (point))
                    (setq indent_amt (- indent_end (point) 1))
                    (unless
                        (loop done
                            (when (= (point) (point-min))
                                (ding)
                                (done nil)
                            ) ; when
                            (previous-logical-line)
                            (beginning-of-line)
                            (setq line_start (point))
                            (end-of-line)
                            (when (/= line_start (point)) ; skip over empty lines
                                (back-to-indentation)
                                (setq indent_end (point))
                                (beginning-of-line)
                                (when (< (- indent_end (point)) indent_amt)
                                    (done t)
                                ) ; when
                            ) ; when
                        ) ; loop
                        (break)
                    ) ; unless
                )
                (t ; on line with no leading whitespace
                    (ding)
                    (break)
                )
            ) ; cond
        ) ; let
        (setq count (- count 1))
        (when (<= count 0)
            (break)
        ) ; when
    ) ; loop
    (back-to-indentation)
) ; prev_less_indent

Feel free to show us how it should be “refactored and code moved out
to functions/methods”.