bug#20640: 24.5; lexical-binding should work like a normal file-local variable

[Glenn Morris]

Stefan Monnier wrote:

>>> Allowing it at the end of the file, would require jumping to the end of
>>> the file first, and then starting over from the beginning.
>>> That'd be a very bad requirement.
>> Why? We're going to have to read that page eventually anyway.
>
> Because we can't read the first page correctly until we know whether it
> should be read in lexical-binding mode or in dynamic-binding mode.

A few years ago, we said (IIUC) it was desirable:

http://debbugs.gnu.org/10605
http://lists.gnu.org/archive/html/emacs-devel/2012-01/msg00543.html

Or have speed-ups in uncompiled code shifted the balance?

(But no-one shows any sign of doing anything, so it's all academic.)