bug#11782: 24.1; closure is not self-quoting

[Christopher Schmidt <christopher@ch.ristopher.com>]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

Hi Stefan,

> Could you expand on why you think it's severe?

I think this issue is severe because the behaviour is odd and follows
neither other mature Lispy languages nor the reference manual.

    (info "(elisp)Lambda Expressions")

    In Emacs Lisp, such a list is valid as an expression--it evaluates
    to itself.

As I said 11 month ago, I hit on this issue a few times already.  So did
others.  In most cases I had a lambda form that was eval'ed twice due to
macro expansion.

    ;; -*- lexical-binding: t -*-

    (defmacro a ()
      (let ((l (lambda () )))
        `(funcall ,l)))

    (a)

I realise there is a technical need for lambda's to evaluate to closures
in a lexical environment.  Are there any technical reasons for lexical
closures to not self-quote?

BTW I am perfectly fine with just fixing the docs.

        Christopher