VimL: get/set multibyte environment variable names

[erw7]

• nvim --version: NVIM v0.4.0-246-g1694f445e
• Vim (version: ) behaves differently?
  • In Windows vim, if I complement the variable name, I can display that value with echo.
  • It is the same as neovim in Linux vim.
  • In Windows and Linux, vim can not set variables with let same as neovim.
• Operating system/version: Microsoft Windows [Version 6.1.7601]
• Terminal name/version: cmd.exe
• $TERM: win32con

Steps to reproduce using nvim -u NORC

chcp 932
set aあ=abc
nvim -u NORC
:echo $aあ
or
:let $iい='abc'

Actual behaviour

It is displayed as follows.

E15: Invalid expression: <81><82>
or
E15: Invalid expression: $iい='abc'
E488: Trailing characters

Expected behaviour

I understand that this will be the specification of vim script. I also understand that few people use multibyte for environment variable names. I do not know if we need to fix it to be honest. However, it is preferable to be able to deal with it unless it is prohibited to include multibyte in environment variable names.

[justinmk]

:echo $aあ works in Windows Vim?

Does this work in Nvim on Windows:

:echo expand('$aあ')

On linux I see this in bash:

$ export 'XTEST_1AaあB'=foo
-bash: export: `XTEST_1AaあB=foo': not a valid identifier

[erw7]

It is very strange, but if I enter the variable name by completion in the next step, it will work with Windows vim. And if I enter $aあ from the keyboard, nothing is displayed.

vim -u NONE -N
:echo $a<tab>

It is as follows in zsh:

$ export 'XTEST_1AaあB'=foo
$ echo XTEST_1AaあB
foo

Even tcsh and fish can use multibyte for environment variable names.

[erw7]

Does this work in Nvim on Windows:

No, $aあ is displayed.