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From: Yuan Fu <casouri@gmail.com>
To: help-gnu-emacs@gnu.org
Subject: Plist-put changes literal argument
Date: Wed, 2 Sep 2020 19:55:25 -0400	[thread overview]
Message-ID: <30E631BA-6845-43C1-AB5E-4C02C4F44780@gmail.com> (raw)

I found plist-put changes the literal argument I pass to a function:

(defun test ()
  (test-2 '(:a b)))

(defun test-2 (form)
  (print form)
  (plist-put form :a 'c)
  nil)

(progn (test) (test))

(:a b)

(:a c)
nil

I thought Elisp is pass-by-copy? Is this expected?

P.S., (setf (alist-get )) does the same, I guess this IS expected?

Yuan



             reply	other threads:[~2020-09-02 23:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-02 23:55 Yuan Fu [this message]
2020-09-02 23:59 ` Plist-put changes literal argument Yuan Fu
2020-09-03  0:18   ` Yuan Fu
2020-09-03  0:53     ` Noam Postavsky
2020-09-05 15:55     ` Philipp Stephani
2020-09-06 15:23       ` Yuan Fu
2020-09-05 15:53   ` Philipp Stephani

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