From: Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>
To: help-gnu-emacs@gnu.org
Subject: Re: [External] : Re: Lexical vs. dynamic: small examples?
Date: Sat, 28 Aug 2021 03:36:53 +0200 [thread overview]
Message-ID: <87y28mbb9m.fsf@zoho.eu> (raw)
In-Reply-To: jwvbl5l2iwn.fsf-monnier+emacs@gnu.org
Stefan Monnier via Users list for the GNU Emacs text editor wrote:
> Of course. If the compiler says it's "not known to be
> defined" that means the var isn't bound lexically (either
> that, or there's a bug in the compiler), so it can only make
> sense if the var is global or dynamically scoped (and both
> are closely related).
Check this out, here we seemingly define a global variable
which isn't special/dynamic (because `special-variable-p' says
it isn't) but it behaves like one anyway so I guess it is?
Maybe it (the predicate) can only look at the definition and
if it doesn't have an initial/default value it can't tell
... something?
;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;; https://dataswamp.org/~incal/emacs-init/scope.el
;;;
;;; g = global
;;; sd = special/dynamic
;;; ls = lexical/static
;;; v = variable
(defvar gsd-v 1) ; 1
(special-variable-p 'gsd-v) ; t
(defvar gls-v)
(setq gls-v 2) ; 2
(special-variable-p 'gls-v) ; nil
(defun fun-lol ()
(list gsd-v gls-v v) )
(setq lexical-binding nil)
(let ((gsd-v 100)
(gls-v 200)
(v 300) )
(list (list gsd-v gls-v v)
(fun-lol) )) ; ((100 200 300) (100 200 300))
(setq lexical-binding t)
(let ((gsd-v 100)
(gls-v 200)
(v 300) )
(list (list gsd-v gls-v v)
(fun-lol) )) ; DNC, lexical/static `let' binding v undefined in fun-lol
(defun fun-lol-2 ()
(list gsd-v gls-v) )
(let ((gsd-v 100)
(gls-v 200)
(v 300) )
(list (list gsd-v gls-v v)
(fun-lol-2) )) ; ((100 200 300) (100 200))
--
underground experts united
https://dataswamp.org/~incal
next prev parent reply other threads:[~2021-08-28 1:36 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-14 3:34 Lexical vs. dynamic: small examples? Eduardo Ochs
2021-08-14 3:56 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 4:12 ` Eduardo Ochs
2021-08-14 7:35 ` tomas
2021-08-14 16:00 ` Eduardo Ochs
2021-08-14 19:41 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:42 ` tomas
2021-08-14 19:31 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:31 ` tomas
2021-08-14 21:26 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 21:29 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 13:35 ` [External] : " Drew Adams
2021-08-14 16:15 ` Eduardo Ochs
2021-08-14 19:00 ` Gregory Heytings
2021-08-14 20:16 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:23 ` Gregory Heytings
2021-08-14 21:05 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 21:13 ` tomas
2021-08-14 21:28 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:41 ` tomas
2021-08-15 0:29 ` [External] : " Drew Adams
2021-08-15 0:52 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 1:04 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 1:18 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 4:44 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 5:02 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 15:49 ` Drew Adams
2021-08-15 18:49 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 21:55 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-15 22:04 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 21:57 ` Drew Adams
2021-08-15 22:20 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:54 ` Drew Adams
2021-08-15 23:16 ` Drew Adams
2022-01-09 7:08 ` Jean Louis
2022-01-09 15:03 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 23:42 ` Arthur Miller
2021-08-15 22:02 ` Lars Ingebrigtsen
2021-08-15 22:22 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:44 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-21 3:38 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-24 2:08 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-25 23:34 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:40 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26 0:10 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26 0:44 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26 17:01 ` FW: " Drew Adams
2021-08-26 23:05 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:46 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:47 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-26 0:57 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-28 1:36 ` Emanuel Berg via Users list for the GNU Emacs text editor [this message]
2021-08-28 1:41 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:44 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:58 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-15 23:13 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 23:56 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-16 0:43 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 15:42 ` FW: " Drew Adams
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