Re: [External] : Re: [NonGNU ELPA] New package: Denote-Refs

[Philip Kaludercic]

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

>> >> -(defgroup denote-refs nil
>> >> +(defgroup denote-refs '()
>> > Why?
>> 
>> It is just a personal preference of mine, since the argument MEMBER is
>> an alist.  I think that '() makes it more explicit that this is a list,
>> as opposed to nil which might also be taken to be a truth value.  I
>> guess () would do as well...
>
> Yes, () would do as well - in fact better, since it
> doesn't suggest any possibility that '() represents
> something different from ().
>
> You don't quote nil or t, do you?  Or 42 or "foo" or
> :bar.  Why quote () then?

In this case it doesn't matter, because () is self-evaluating, but (foo)
isn't, so to me it seems more consistent to treat () as a list where I
want to make it explicit that I am inhibiting evaluation.

> As the manual says:
>
>   As far as the Lisp reader is concerned, '()' and 'nil'
>   are identical: they stand for the same object, the
>   symbol 'nil'.  The different ways of writing the symbol
>   are intended entirely for human readers.  After the
>   Lisp reader has read either '()' or 'nil', there is no
>   way to determine which representation was actually
>   written by the programmer.
>
>   In this manual, we write '()' when we wish to emphasize
>   that it means the empty list, and we write 'nil' when
>   we wish to emphasize that it means the truth value FALSE.
>   That is a good convention to use in Lisp programs also.
>
> And yes, it's a good convention -- +1 for that.