bug#45333: complex command history should not save optional nil parameters

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Lars Ingebrigtsen [2022-07-07 16:52:05] wrote:
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> Sorry, both (foo [bar zot] ...) and "doing low level stuff" sound a bit
>> too hypothetical for me to get a sense of what we're talking about.
>>
>> More specifically I don't know of any use of advertized signature that
>> presents the args with a [...] notation, 
>
> ---
> setq is a special form in src/eval.c.
>
> (setq [SYM VAL]...)
> ---

Ah, so you're not talking about advertised-calling-convention!?

>> and I can't remember ever needing a pretty arglist when working on
>> "low-level stuff".
> You don't need the pretty arglist, but it can be informative.

Usually in those cases I look at the source, which is even
more informative.

Clearly, there is some info we "throw away" or make harder to get to,
but to the extent that you can get it back by visiting the source code,
I don't see a good reason to spend much effort trying to cater to those
very rare needs.

Basically, if we want to go there, we start to want to distinguish
between:
- the "final and pretty" advertized arglist
- the "final and pretty" arglist but disregarding advertised-calling-convention
- the original arglist rather than the one stashed in the docstring.
- the raw arglist seen by the interpreter.
I doubt very many chunks of code will know which level to choose (and
even fewer will have a good justification for that choice).


        Stefan