Subject: bug#61281: “`(a \, b)” equals to “`(a . , b)”

From: Andreas Schwab <[email-masked]>
Date: Mon, 06 Feb 2023 10:40:36 +0100

On Feb 06 2023, Michael Heerdegen wrote:

> S-exps are defined recursively.  ",X" is read syntax of a valid s-exp,
> and I don't think we want to make the reader raise an error for it.

FWIW, clisp generates an error if the comma occurs outside of backquote.
If you quote the comma, it is treated as an ordinary symbol character.

$ clisp -q -x ',X'
*** - READ: comma is illegal outside of backquote
$ clisp -q -x '\,X'
*** - SYSTEM::READ-EVAL-PRINT: variable |,X| has no value

$ clisp -q -x '`\,X'
|,X|

-- 
Andreas Schwab, SUSE Labs, [email-masked]
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