by shigemk2

当面は技術的なことしか書かない

downcase-region と C-x C-l

意味なくdowncase-regionをやりたくって、
C-x C-lをやると、以下のようなメッセージが出る。

You have typed C-x C-l, invoking disabled command downcase-region.
It is disabled because new users often find it confusing.
Here's the first part of its description:

Convert the region to lower case. In programs, wants two arguments.
These arguments specify the starting and ending character numbers of
the region to operate on. When used as a command, the text between
point and the mark is operated on.

Do you want to use this command anyway?

You can now type
y to try it and enable it (no questions if you use it again).
n to cancel--don't try the command, and it remains disabled.
SPC to try the command just this once, but leave it disabled.
! to try it, and enable all disabled commands for this session only.

「新しいユーザーが混乱するから」
理由については、たぶんこれ以上のことは書いていないのだろう。

一旦yを押して、そのあとまたdisabledにしたいときは、

(put 'downcase-region 'disabled t)

と書けばいいしenabledにしたいときは

(put 'downcase-region 'disabled nil)

と書けばいい。