I need help updating config code from vimscript to lua

Question

About three years ago, I had gathered chunks of code from the net and made my init.vim config file. Now, with Lua released, I am unable to convert it.

And it's down to you folks whether you can help me. You are my last hope.

Yes, I've read the documentation and whatnot. Still, I don't get it. Most of the code in my init.vim file are complex while I can do only simpler ones.

au TextYankPost * silent! lua vim.highlight.on_yank {higroup="IncSearch", timeout=300}

au BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g'\"" | endif

" type :messages to see all the changed files
set autoread
autocmd FocusGained,BufEnter,CursorHold,CursorHoldI *
   \ if mode() !~ '\v(c|r.?|!|t)' && getcmdwintype() == '' | checktime | endif
autocmd FileChangedShellPost *
  \ echohl WarningMsg | echom "File " . expand('<afile>') . " changed on disk. Buffer reloaded." | echohl None

---

function! TabLcd()
    let current_tab = tabpagenr()
    tabdo lcd %:p:h
    execute 'tabnext' current_tab
endfunction

nnoremap <silent> <leader>lcd :call TabLcd()<cr>
nnoremap <leader>cd :execute 'cd' getcwd(-1)<cr>

This block is solved by me: https://vi.stackexchange.com/a/43276/36876

" No highlight after search - triggers on motion or going into insert mode
noremap <expr> <Plug>(StopHL) execute('nohlsearch')[-1]
noremap! <expr> <Plug>(StopHL) execute('nohlsearch')[-1]

fu! HlSearch()
    let s:pos = match(getline('.'), @/, col('.') - 1) + 1
    if s:pos != col('.')
        call StopHL()
    endif
endfu

fu! StopHL()
    if !v:hlsearch || mode() isnot 'n'
        return
    else
        sil call feedkeys("\<Plug>(StopHL)", 'm')
    endif
endfu

augroup SearchHighlight
au!
    au CursorMoved * call HlSearch()
    au InsertEnter * call StopHL()
augroup end

This block is solved by @vivian-de-smedt in https://vi.stackexchange.com/a/43279/36876

if !exists("g:os")
    if has("win64") || has("win32") || has("win16")
        let g:os = "Windows"
    else
        let g:os = substitute(system('uname'), '\n', '', '')
    endif
endif

This block solved in https://vi.stackexchange.com/a/43284/36876

tnoremap <Esc> <C-\><C-n>

" https://vi.stackexchange.com/a/22327/36876
if has('nvim')
    augroup terminal_setup | au!
        autocmd TermOpen * nnoremap <buffer><LeftRelease> <LeftRelease>i
    augroup end
endif

function! TermWrapper(command) abort
    if !exists('g:split_term_style') | let g:split_term_style = 'vertical' | endif
    if g:split_term_style ==# 'vertical'
        let buffercmd = 'vnew'
    elseif g:split_term_style ==# 'horizontal'
        let buffercmd = 'new'
    else
        echoerr 'ERROR! g:split_term_style is not a valid value (must be ''horizontal'' or ''vertical'' but is currently set to ''' . g:split_term_style . ''')'
        throw 'ERROR! g:split_term_style is not a valid value (must be ''horizontal'' or ''vertical'')'
    endif
    exec buffercmd
    if exists('g:split_term_resize_cmd')
        exec g:split_term_resize_cmd
    endif
    exec 'term ' . a:command
    exec 'setlocal nornu nonu'
    exec 'startinsert'
endfunction

command! -nargs=0 Compile call TermWrapper(printf('g++ -std=c++17 -O2 -Wall %s -o %s.out', expand('%'), expand('%:r')))
autocmd FileType cpp nnoremap <F9> <Esc>:w <bar> Compile<CR>

command! -nargs=0 Run call TermWrapper(printf('./%s.out', expand('%:r')))
autocmd FileType cpp nnoremap <F10> :Run<CR>

command! -nargs=0 CompileAndRun call TermWrapper(printf('g++ -std=c++17 -O2 -Wall %s -o %s.out && ./%s.out', expand('%'), expand('%:r'), expand('%:r')))
autocmd FileType cpp nnoremap <F12> <Esc>:w <bar> CompileAndRun<CR>

let g:split_term_style = 'horizontal'
let g:split_term_resize_cmd = 'resize 30'
set splitbelow

This block is solved in https://vi.stackexchange.com/a/43287/36876

Answer 1

Here is the aggregated solution:

if vim.fn.exists('g:os') == 0 then
    local is_windows = vim.fn.has("win64") == 1 or vim.fn.has("win32") == 1 or vim.fn.has("win16") == 1
    if is_windows then
        vim.g.os = "Windows"
    else
        local uname_output = vim.fn.system('uname')
        vim.g.os = string.gsub(uname_output, '\n', '')
    end
end

function TabLcd()
    local current_tab = vim.fn.tabpagenr()
    vim.cmd("tabdo <commands>")
    vim.cmd("execute 'tabnext' " .. current_tab)
end

vim.api.nvim_set_keymap('n', '<leader>lcd', ':lua TabLcd()<CR>', { noremap = true, silent = true })

vim.api.nvim_set_keymap('t', '<Esc>', '<C-\\><C-n>', { noremap = true })

if vim.fn.has('nvim') == 1 then
    vim.cmd[[
        augroup terminal_setup
            autocmd!
            autocmd TermOpen * nnoremap <buffer><LeftRelease> <LeftRelease>i
        augroup end
    ]]
end

function TermWrapper(command)
    if not vim.g.split_term_style then
        vim.g.split_term_style = 'vertical'
    end
    local buffercmd
    if vim.g.split_term_style == 'vertical' then
        buffercmd = 'vnew'
    elseif vim.g.split_term_style == 'horizontal' then
        buffercmd = 'new'
    else
        vim.api.nvim_err_writeln("ERROR! g:split_term_style is not a valid value (must be 'horizontal' or 'vertical' but is currently set to '" .. vim.g.split_term_style .. "')")
        error("ERROR! g:split_term_style is not a valid value (must be 'horizontal' or 'vertical')")
    end
    vim.cmd(buffercmd)
    if vim.g.split_term_resize_cmd then
        vim.cmd(vim.g.split_term_resize_cmd)
    end
    vim.cmd('term ' .. command)
    vim.cmd('setlocal nornu nonu')
    vim.cmd('startinsert')
end

vim.cmd([[command! -nargs=0 Compile lua TermWrapper(string.format('g++ -std=c++17 -O2 -Wall %s -o %s.out', vim.fn.expand("%"), vim.fn.expand("%:r")))]])
vim.cmd('autocmd FileType cpp nnoremap <F9> <Esc>:w <bar> Compile<CR>')

vim.cmd([[command! -nargs=0 Run lua TermWrapper(string.format("./%s.out", vim.fn.expand("%:r")))]])
vim.cmd('autocmd FileType cpp nnoremap <F10> :Run<CR>')

vim.cmd([[command! -nargs=0 CompileAndRun lua TermWrapper(string.format('g++ -std=c++17 -O2 -Wall %s -o %s.out && ./%s.out', vim.fn.expand("%"), vim.fn.expand("%:r"), vim.fn.expand("%:r")))]])
vim.cmd('autocmd FileType cpp nnoremap <F12> <Esc>:w <bar> CompileAndRun<CR>')

vim.g.split_term_style = 'horizontal'
vim.g.split_term_resize_cmd = 'resize 30'
vim.opt.splitbelow = true

vim.api.nvim_set_keymap('n', '<Plug>(StopHL)', "execute('nohlsearch')[-1]", { noremap = true, expr = true })
vim.api.nvim_set_keymap('i', '<Plug>(StopHL)', "execute('nohlsearch')[-1]", { noremap = true, expr = true })

function HlSearch()
    local pos = vim.fn.match(vim.fn.getline('.'), vim.fn.getreg('/'), vim.fn.col('.') - 1) + 1
    if pos ~= vim.fn.col('.') then
        StopHL()
    end
end

function StopHL()
    if not vim.v.hlsearch or vim.fn.mode() ~= 'n' then
        return
    else
        vim.cmd[[silent! call feedkeys("\<Plug>(StopHL)", 'm')]]
    end
end

local searchHighlightGrp = vim.api.nvim_create_augroup('SearchHighlight', { clear = true })
vim.api.nvim_create_autocmd({"CursorMoved"}, {group = searchHighlightGrp, pattern = '*', callback = HlSearch})
vim.api.nvim_create_autocmd({"InsertEnter"}, {group = searchHighlightGrp, pattern = '*', callback = StopHL})

vim.api.nvim_create_autocmd({'TextYankPost'}, { callback = function() vim.highlight.on_yank {higroup="IncSearch", timeout=300} end })

vim.api.nvim_create_autocmd({'BufReadPost'}, { callback = function()
    local mark = vim.api.nvim_buf_get_mark(0, '"')[1]
    if mark > 1 and mark < vim.api.nvim_buf_line_count(0) then
        vim.api.nvim_command([[exe "normal! g'\""]])
    end
end
})

vim.o.autoread = 1

vim.api.nvim_create_autocmd({'FocusGained', 'BufEnter', 'CursorHold', 'CursorHoldI'}, { callback = function()
    if not string.match(vim.fn.mode(), '^(c|r.?|!|t)') and vim.api.nvim_eval('getcmdwintype()') == '' then
        vim.cmd([[checktime]])
    end
end
})

vim.api.nvim_create_autocmd({'FileChangedShellPost'}, { callback = function()
    vim.api.nvim_command([[
        echohl WarningMsg
        echom "File " . expand('<afile>') . " changed on disk. Buffer reloaded."
        echohl None
        ]])
end
})