From: John Mastro <john.b.mastro@gmail.com>
To: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>
Cc: Kaushal Modi <kaushal.modi@gmail.com>
Subject: Re: Canonical way of marking a buf local var to be safe if nil/t?
Date: Thu, 12 May 2016 10:39:04 -0700 [thread overview]
Message-ID: <CAOj2CQSVe5qp22mKhac4YW-X2Sr+9DnVzrqT1tNy-h_FaMqb_w@mail.gmail.com> (raw)
In-Reply-To: <CAFyQvY0DT6qW6jb-TD4ZVthi51chafVoaO1hPW8nu6+ZpizbPQ@mail.gmail.com>
Kaushal Modi <kaushal.modi@gmail.com> wrote:
> What would be a canonical way (if any) of setting a var to be a safe buffer
> local variable as long as its value is either nil or t?
>
> I use
>
> (put 'my-foo-var 'safe-local-variable (lambda (val) (or (equal val nil)
> (equal val t))))
Use `booleanp':
booleanp is a compiled Lisp function in ‘subr.el’.
(booleanp OBJECT)
Return t if OBJECT is one of the two canonical boolean values: t or nil.
Otherwise, return nil.
--
john
next prev parent reply other threads:[~2016-05-12 17:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-12 17:32 Canonical way of marking a buf local var to be safe if nil/t? Kaushal Modi
2016-05-12 17:39 ` John Mastro [this message]
2016-05-12 17:41 ` Kaushal Modi
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