bug#37051: 26.2.90; feature request: C-x 8 <SYMBOL> Prefix Command for letter with macron

[VanL]

> On 20 Aug 2019, at 00:44, Robert Pluim <rpluim@gmail.com> wrote:
> 
>    VanL> I'd like to be able to type the 'a' and 'i' with macron in 'Cháng
>    VanL> Xiāng Sī (Everlasting Longing) by Bai Juyi'.
> 
> Would you consider using the chinese-sisheng input method? That has
> mappings for all of those. In fact, digging some more, thereʼs the
> hawaiian-prefix method as well, which has far fewer mappings, so
> shouldn't interfere too much with normal typing.
> 
> Otherwise it could be added to the C-x 8 map, but Iʼm having a hard
> time finding a prefix thatʼs both free and reasonably mnemonic for
> MACRON, unless we want to turn 'C-x 8 =' into a prefix map, with
> 'C-x 8 = =' meaning 'insert MACRON'.

How about a C-u before `C-x 8 -         ­' for to `insert MACRON'?

I fail to find instructions to use chinese-sisheng in [1] and the listings from 
describe-mode, describe-bindings don't have `ī' in them, for example.

C-x <RET> C-\ h <TAB> ; has no hawaiian-prefix method completion but hebrew.

-- [1]
  info:emacs#Input Methods
  info:emacs#Select Input Method
  info:emacs#International