Add evaluation of selected code as comment

EvaluateAsComment.vim

" From https://old.reddit.com/r/neovim/comments/1c3gf93/commentreplnvim_run_code_from_your_buffer_and/
"
" Add the following lines to `ftplugin/{python,sh,zsh,lua,perl, ...}.vim
" and call :EvaluateAsComment to add the evaluation of the selected lines as a comment:
"
" print(1+2)
"
" becomes
"
" # 3
" print(1+2)
"
" Alternatively, https://github.com/gpanders/vim-medieval evaluates code in a (markdown) code block

let b:evaluator = &filetype
command! -buffer -range -bar EvaluateAsComment
      \ silent <line1>,<line2>copy<line2> |
      \ exe "<line1>,<line2>!"..b:evaluator.." | sed 's/^.*$/"..printf(escape(&commentstring, '\/.*^$[]#'), '\0').."/'"