How to implement a symbol keyboard layer in Vim?

Question

I recently came across this question: Mapping symbols and special characters to home row in insert mode, which introduced me to the idea of a symbol layer on the keyboard. This seems like a nice thing to have. The post in question got bogged down in the specifics of the layout of the symbols.

The question I have is how to implement such a layer in vim/neovim?

That is, prefix key + 'a-z' results in a symbol (i.e. ( ).

I would prefer it if the prefix key was not and a relatively compact solution rather than mapping every key (if possible). My focus is currently on insert mode, however it could be useful in normal mode also, and maybe should be system wide rather than implemented in Vim.

Edit: The system I am using would be Linux/Ubuntu in this instance.

Answer 1

I can't comment on a system wide solution. But here is what I would propose for Vim/Neovim:

The basic would be to do (under the assumption you select , as the prefix:

inoremap ,a /
inoremap ,z (
...

Remark: The drawback of such mapping is that to enter a pure , you'll get a small delay because Vim will give you the chance to complement the sequence.

You'll need one line per key unless you have the mapping into a Vim dictionary and create the mapping into a loop.

let c2home = {'a': '/', 'z': '('}
for c in keys(c2home)
  execute 'inoremap ,' . c ' ' . c2home[c]
endfor