Plug-Vim based vimrc with fzf, nerd tree, terminal windows and LSP for code-completion

.vimrc

" You can revert the settings after the call like so:
"   filetype indent off   " Disable file-type-specific indentation
"   syntax off            " Disable syntax highlighting

set clipboard=unnamed
set nu
set nocompatible
set backspace=indent,eol,start " Allows backspace to work
filetype off                  " required

" Installs plug if not already installed
let data_dir = '~/.vim'
if empty(glob(data_dir . '/autoload/plug.vim'))
  silent execute '!curl -fLo '.data_dir.'/autoload/plug.vim --create-dirs  https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim'
  autocmd VimEnter * PlugInstall --sync | source $MYVIMRC
endif

" The default plugin directory is '~/.vim/plugged'
call plug#begin()

" Git plugin
Plug 'tpope/vim-fugitive'

" syntax checking plugin
Plug 'scrooloose/syntastic'

" Side directory
Plug 'scrooloose/nerdtree'

" Powerful commenting help
Plug 'preservim/nerdcommenter'

" Using a tagged release; wildcard allowed (requires git 1.9.2 or above)
Plug 'fatih/vim-go', { 'tag': '*' }

" Plugin outside ~/.vim/plugged with post-update hook
Plug 'junegunn/fzf', { 'do': { -> fzf#install() } }
Plug 'junegunn/fzf.vim'
Plug 'vim-airline/vim-airline'

" A collection of language packs for Vim.
Plug 'sheerun/vim-polyglot'

" provides Rust file detection, syntax highlighting, formatting, Syntastic
" integration, and more.
Plug 'rust-lang/rust.vim'

" Custom popup menu with snippet support
Plug 'neoclide/coc.nvim', {'branch': 'release'}

" File searching
Plug 'dyng/ctrlsf.vim'

" Initialize plugin system
" - Automatically executes `filetype plugin indent on` and `syntax enable`.
call plug#end()

set rtp+=~/.vim/plugged/fzf

fu GetTerm()
    terminal
    wincmd x
    res 60
endfu

" Creates a terminal window
nnoremap <C-y> :call GetTerm()<CR>

" Resize screen height
nnoremap <silent> <Leader>= :exe "resize " . (winheight(0) * 3/2)<CR>
nnoremap <silent> <Leader>- :exe "resize " . (winheight(0) * 2/3)<CR>

" NERDTree COMMANDS

" mappings
nnoremap <leader>n :NERDTreeFocus<CR>
nnoremap <C-n> :NERDTree<CR>
nnoremap <C-t> :NERDTreeToggle<CR>

" Start NERDTree when Vim is started without file arguments.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 0 && !exists('s:std_in') | NERDTree | endif

" Exit Vim if NERDTree is the only window left.
autocmd BufEnter * if tabpagenr('$') == 1 && winnr('$') == 1 && exists('b:NERDTree') && b:NERDTree.isTabTree() |
    \ quit | endif

" If another buffer tries to replace NERDTree, put it in the other window, and bring back NERDTree.
autocmd BufEnter * if bufname('#') =~ 'NERD_tree_\d\+' && bufname('%') !~ 'NERD_tree_\d\+' && winnr('$') > 1 |
    \ let buf=bufnr() | buffer# | execute "normal! \<C-W>w" | execute 'buffer'.buf | endif


" FZF COMMANDS
" Ctrl + f
nnoremap <C-f> :Files<CR>
" Ctrl + h
nnoremap <C-h> :FZF<CR>
" Ctrl + a
nnoremap <C-a> :FZF ~<CR>

" backslash (\) + f
" Searches text in files
nnoremap <silent> <Leader>f :Rg<CR>

" Prevents filename as a match when searching for text in files
command! -bang -nargs=* Rg call fzf#vim#grep("rg --column --line-number --no-heading --color=always --smart-case ".shellescape(<q-args>), 1, {'options': '--delimiter : --nth 4..'}, <bang>0)

" Tell Vim to use ripgrep instead of grep
set grepprg=rg\ --vimgrep\ --smart-case\ --follow

" Syntastic 
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}

let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 1
let g:syntastic_check_on_wq = 0

"""
" COC VIM REQUIREMENTS START
"""
" Some servers have issues with backup files, see #649.
set nobackup
set nowritebackup

" Having longer updatetime (default is 4000 ms = 4 s) leads to noticeable
" delays and poor user experience.
set updatetime=300

" Always show the signcolumn, otherwise it would shift the text each time
" diagnostics appear/become resolved.
" set signcolumn=yes

" Use tab for trigger completion with characters ahead and navigate.
" NOTE: Use command ':verbose imap <tab>' to make sure tab is not mapped by
" NOTE: There's always complete item selected by default, you may want to enable
" no select by `"suggest.noselect": true` in your configuration file.
" other plugin before putting this into your config.
inoremap <silent><expr> <TAB>
      \ coc#pum#visible() ? coc#pum#next(1):
      \ CheckBackspace() ? "\<Tab>" :
      \ coc#refresh()
inoremap <expr><S-TAB> coc#pum#visible() ? coc#pum#prev(1) : "\<C-h>"

" Make <CR> to accept selected completion item or notify coc.nvim to format
" <C-g>u breaks current undo, please make your own choice.
inoremap <silent><expr> <CR> coc#pum#visible() ? coc#pum#confirm()
                              \: "\<C-g>u\<CR>\<c-r>=coc#on_enter()\<CR>"

function! CheckBackspace() abort
  let col = col('.') - 1
  return !col || getline('.')[col - 1]  =~# '\s'
endfunction

" Use <c-space> to trigger completion.
if has('nvim')
  inoremap <silent><expr> <c-space> coc#refresh()
else
  inoremap <silent><expr> <c-@> coc#refresh()
endif

" Use `[g` and `]g` to navigate diagnostics
" Use `:CocDiagnostics` to get all diagnostics of current buffer in location list.
nmap <silent> [g <Plug>(coc-diagnostic-prev)
nmap <silent> ]g <Plug>(coc-diagnostic-next)

" GoTo code navigation.
nmap <silent> gd <Plug>(coc-definition)
nmap <silent> gy <Plug>(coc-type-definition)
nmap <silent> gi <Plug>(coc-implementation)
nmap <silent> gr <Plug>(coc-references)

" Use K to show documentation in preview window.
nnoremap <silent> K :call ShowDocumentation()<CR>

function! ShowDocumentation()
  if CocAction('hasProvider', 'hover')
    call CocActionAsync('doHover')
  else
    call feedkeys('K', 'in')
  endif
endfunction

" Highlight the symbol and its references when holding the cursor.
autocmd CursorHold * silent call CocActionAsync('highlight')

" Symbol renaming.
nmap <leader>rn <Plug>(coc-rename)

" Formatting selected code.
xmap <leader>f  <Plug>(coc-format-selected)
nmap <leader>f  <Plug>(coc-format-selected)

augroup mygroup
  autocmd!
  " Setup formatexpr specified filetype(s).
  autocmd FileType typescript,json setl formatexpr=CocAction('formatSelected')
  " Update signature help on jump placeholder.
  autocmd User CocJumpPlaceholder call CocActionAsync('showSignatureHelp')
augroup end

" Applying codeAction to the selected region.
" Example: `<leader>aap` for current paragraph
xmap <leader>a  <Plug>(coc-codeaction-selected)
nmap <leader>a  <Plug>(coc-codeaction-selected)

" Remap keys for applying codeAction to the current buffer.
nmap <leader>ac  <Plug>(coc-codeaction)
" Apply AutoFix to problem on the current line.
nmap <leader>qf  <Plug>(coc-fix-current)

" Run the Code Lens action on the current line.
nmap <leader>cl  <Plug>(coc-codelens-action)

" Map function and class text objects
" NOTE: Requires 'textDocument.documentSymbol' support from the language server.
xmap if <Plug>(coc-funcobj-i)
omap if <Plug>(coc-funcobj-i)
xmap af <Plug>(coc-funcobj-a)
omap af <Plug>(coc-funcobj-a)
xmap ic <Plug>(coc-classobj-i)
omap ic <Plug>(coc-classobj-i)
xmap ac <Plug>(coc-classobj-a)
omap ac <Plug>(coc-classobj-a)

" Remap <C-m> and <C-b> for scroll float windows/popups.
if has('nvim-0.4.0') || has('patch-8.2.0750')
  nnoremap <silent><nowait><expr> <C-m> coc#float#has_scroll() ? coc#float#scroll(1) : "\<C-f>"
  nnoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? coc#float#scroll(0) : "\<C-b>"
"  inoremap <silent><nowait><expr> <C-m> coc#float#has_scroll() ? "\<c-r>=coc#float#scroll(1)\<cr>" : "\<Right>"
"  inoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? "\<c-r>=coc#float#scroll(0)\<cr>" : "\<Left>"
  vnoremap <silent><nowait><expr> <C-m> coc#float#has_scroll() ? coc#float#scroll(1) : "\<C-f>"
  vnoremap <silent><nowait><expr> <C-b> coc#float#has_scroll() ? coc#float#scroll(0) : "\<C-b>"
endif

" Use CTRL-S for selections ranges.
" Requires 'textDocument/selectionRange' support of language server.
nmap <silent> <C-s> <Plug>(coc-range-select)
xmap <silent> <C-s> <Plug>(coc-range-select)

" Add `:Format` command to format current buffer.
command! -nargs=0 Format :call CocActionAsync('format')

" Add `:Fold` command to fold current buffer.
command! -nargs=? Fold :call     CocAction('fold', <f-args>)

" Add `:OR` command for organize imports of the current buffer.
command! -nargs=0 OR   :call     CocActionAsync('runCommand', 'editor.action.organizeImport')

" Add (Neo)Vim's native statusline support.
" NOTE: Please see `:h coc-status` for integrations with external plugins that
" provide custom statusline: lightline.vim, vim-airline.
set statusline^=%{coc#status()}%{get(b:,'coc_current_function','')}

" Mappings for CoCList
" Show all diagnostics.
nnoremap <silent><nowait> <space>a  :<C-u>CocList diagnostics<cr>
" Manage extensions.
nnoremap <silent><nowait> <space>e  :<C-u>CocList extensions<cr>
" Show commands.
nnoremap <silent><nowait> <space>c  :<C-u>CocList commands<cr>
" Find symbol of current document.
nnoremap <silent><nowait> <space>o  :<C-u>CocList outline<cr>
" Search workspace symbols.
nnoremap <silent><nowait> <space>s  :<C-u>CocList -I symbols<cr>
" Do default action for next item.
nnoremap <silent><nowait> <space>j  :<C-u>CocNext<CR>
" Do default action for previous item.
nnoremap <silent><nowait> <space>k  :<C-u>CocPrev<CR>
" Resume latest coc list.
nnoremap <silent><nowait> <space>p  :<C-u>CocListResume<CR>

" COC CUSTOM
highlight CocFloating ctermbg=8

"""
" COC CODE REQUIREMENTS END
"""