Re: [External] : Re: Default custom file was: Re: Propose to add setup-wizard.el to ELPA

[Po Lu <luangruo@yahoo.com>]

Drew Adams <drew.adams@oracle.com> writes:

> Doesn't matter to your statement, which was only that if something is
> longstanding then it should be kept - a blanket argument for keeping
> the status quo, what's "established".

And it (dynamic binding) has been kept.

> The lack of lexical binding was longstanding.

The lack of lexical binding was a shortcoming.  A shortcoming is not
behaviour, nor is it a feature.  In contrast, defaulting to the init
file if no custom-file is set is behaviour, since it describes how the
program behaves under certain conditions.

In the specific case of lexical binding, the long-standing behaviour
that was preserved was to default to dynamic binding.

> The absence of a `custom-file' by default is "relied on"?  How so?

Emacs would start to behave differently for people who did not explictly
set custom-file if it gained a default value.

> But there's no longer any lack of it.  A change was introduced,
> bucking your rule of not changing whatever's long been the case.

[...]

> What was established was that there was _only_ dynamic binding.
> That's no longer the case.

Again, see what I said about the distinction between behaviour and
shortcomings.

> How so?  Are you talking about a minority of users having to
> explicitly say that they don't want a separate file - e.g.  simply
> setting `custom-file' to nil?

You may call them a "minority", but all people are important.  There is
no need to cause useless churn for people, just because some other
people have differing preferences.

> As opposed to the majority having to say that they do want a separate
> file?

The majority (if it indeed is a majority) have already done so.

> I'm assuming you agree it's generally better, for more people than
> not, to use a separate `custom-file'.

Yes, I agree.  If this discussion was started at the introduction of
`custom-file', then I would certainly have argued for it to have a
default value.

> There are more future than past users, and for a new user the "other
> thing" of longstanding habit doesn't apply.

How many future users there will be is for the future to say, not for
the present, where changing the default value will only serve to churn
the already muddy waters.