From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeff Davis <pgsql@j-davis.com>
cc: Richard Guo <guofenglinux@gmail.com>,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: Assert failure with ICU support
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Comments: In-reply-to Jeff Davis <pgsql@j-davis.com>
	message dated "Thu, 20 Apr 2023 12:47:21 -0700"
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Date: Thu, 20 Apr 2023 15:53:01 -0400
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Jeff Davis <pgsql@j-davis.com> writes:
> On Wed, 2023-04-19 at 16:45 -0400, Tom Lane wrote:
>> +       if (c >= 0x100 || !iscalnum(c))

> I'm curious why you say >= 0x100 rather than >= 0x80?

Right, should be 0x80, my thinko.

> What's the purpose of the error? Is it to catch mistakes, or is it to
> reserve room for adding new escape sequences in the future?

As I read it, it's meant to leave room for defining more escapes.
If we allowed \x for any non-currently-defined "x" to just be "x",
then there would be a compatibility problem if we wanted to make
it mean something else.  But I think it's sufficient to reserve
the ASCII letters for that purpose.

			regards, tom lane