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bug#8479: 24.0.50; Strange error message upon M-z M-z
From: |
Kevin Rodgers |
Subject: |
bug#8479: 24.0.50; Strange error message upon M-z M-z |
Date: |
Wed, 13 Apr 2011 20:05:40 -0600 |
User-agent: |
Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9.2.15) Gecko/20110303 Thunderbird/3.1.9 |
On 4/12/11 12:00 AM, Eli Zaretskii wrote:
From: Kevin Rodgers<kevin.d.rodgers@gmail.com>
Date: Mon, 11 Apr 2011 23:15:50 -0600
Yes, but why is M-z not a character?
Because the "M-" part sets bits in the area outside the valid range of
character code points.
This is what I was looking for, in the Meta-Character Syntax section of the
Emacs Lisp manual:
A "meta character" is a character typed with the <META> modifier key.
The integer that represents such a character has the 2**27 bit set. We
use high bits for this and other modifiers to make possible a wide
range of basic character codes.
In a string, the 2**7 bit attached to an ASCII character indicates a
meta character; thus, the meta characters that can fit in a string have
codes in the range from 128 to 255, and are the meta versions of the
ordinary ASCII characters. *Note Strings of Events::, for details
about <META>-handling in strings.
--
Kevin Rodgers
Denver, Colorado, USA