Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> As for future Emacsen, I contend that we won't want to change how this
>> lexes in the future - it would break let-alist, for one thing.
>>
>> Incidentally, making it easier to work with let-alist was one of my main
>> motivations for this change, since it ubiquitously uses symbols which
>> start with ".".
>
> Thanks, it's good to have a clear use-case.  You might want to mention
> it in the commit message (tho at least now it's in the associated bug thread).

Sure, done in the attached revised patch.

> How often/much do we care about the printed form of `let-alist` expressions?

Not often, it's mostly just that it's more convenient when hacking on it
(as I was a while back to add numeric indexing), and I figured it was a
harmless change.

> Maybe limiting the effect to ". at the beginning of symbol doesn't need
> to be a escaped if the second char is a letter" would be good enough?

That sounds reasonable to me, done in the attached patch.