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Re: [External] : Re: Lexical vs. dynamic: small examples?
From: |
Emanuel Berg |
Subject: |
Re: [External] : Re: Lexical vs. dynamic: small examples? |
Date: |
Sat, 28 Aug 2021 03:36:53 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) |
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
- Re: [External] : Re: Lexical vs. dynamic: small examples?, (continued)
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Stefan Monnier, 2021/08/23
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- FW: [External] : Re: Lexical vs. dynamic: small examples?, Drew Adams, 2021/08/26
- Re: FW: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/26
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Stefan Monnier, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/25
- Re: [External] : Re: Lexical vs. dynamic: small examples?,
Emanuel Berg <=
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/27
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/15
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Stefan Monnier, 2021/08/15
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/15
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Stefan Monnier, 2021/08/15
- Re: [External] : Re: Lexical vs. dynamic: small examples?, Emanuel Berg, 2021/08/15
- FW: [External] : Re: Lexical vs. dynamic: small examples?, Drew Adams, 2021/08/15