Conquer of Completion

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Coc is an intellisense engine for vim8 & neovim. It only works on vim >= 8.1 and neovim >= 0.3.1

It's a completion framework, language server client which support extension features of VSCode

True snippet and additional text edit support

Checkout doc/coc.txt for vim interface.

Why?

• 🚀 Fast: instant increment completion, increment buffer sync using buffer update events.
• 💎 Reliable: typed language, tested with CI.
• 🌟 Featured: full LSP support
• ❤️ Flexible: configured as VSCode, extensions works like VSCode

Completion experience

You might wondering why another completion engine since there're already widely used YouCompleteMe and deoplete.nvim.

Below is the reasons that lead to coc.nvim build it's own engine:

• Full LSP completion support, especially snippet and additionalTextEdit feature, you'll understand why it's awesome when you experience it with coc extension like coc-tsserver.
• Does completion resolve on completion item change. The detail from complete item is echoed after selected, we will have floating window for documentation when floating window is supported.
• Start completion without timer. The completion would start after you type first letter of word by default, and filtered with new input when completion finished, while some completion engine use timer to trigger completion and you always have to wait after type character.
• Realtime buffer keywords. Coc generate buffer keywords on buffer change in background (with debounce), while some completion engines use cache which could be wrong sometimes. And Locality bonus feature from VSCode is enabled by default.
• Filter completion items when possible. When your does fuzzy filter with completion items (which would trigger TextChangedI during completion), some completion engines would trigger new completion, but coc filter the items when possible which makes coc much faster. Filter completion items on backspace is also supported.

Table of contents

• Installation

  For vim-plug user. Add:

  Plug 'neoclide/coc.nvim', {'tag': '*', 'do': { -> coc#util#install()}}

  Or build from source code by install nodejs and yarn

  curl -sL install-node.now.sh/lts | sh
  curl --compressed -o- -L https://yarnpkg.com/install.sh | bash

  And add:

  Plug 'neoclide/coc.nvim', {'tag': '*', 'do': 'yarn install'}

  to your .vimrc or init.vim, restart vim and run :PlugInstall.

  For other plugin manager, run command :call coc#util#build() to build coc from source code.

  Note: for vim user, global installed vim-node-rpc module required.

  Note: to build from master, don't use 'tag': '*' in Plug command.

  Note: The first time of building from source code could be slow.

• Completion with sources

• Using snippets

• Using extensions

• Using list

• Using configuration file

• Language servers

  • Supported features

  • Register custom language servers

    • Dart
    • Flow
    • C/C++/Objective-C
    • Go
    • PHP
    • Dockerfile
    • Bash
    • Lua
    • OCaml and ReasonML

• Statusline integration

• Debug language server

• Debug coc.nvim

• F.A.Q

Completion sources

Completion for words of buffers and file path are supported by default.

For other completion sources, check out:

• coc-sources: includes some common completion source extensions.
• coc-neco: viml completion support.
• coc-neoinclude: neoinclude integration.

Or you can create custom source.

Extensions

Extension are powerful than configured language server. Checkout Using coc extensions.

• coc-json for json.
• coc-tsserver for javascript and typescript.
• coc-html for html, handlebars and razor.
• coc-css for css, scss and less.
• coc-vetur for vue, use vetur.
• coc-java for java, use eclipse.jdt.ls.
• coc-solargraph for ruby, use solargraph.
• coc-rls for rust, use Rust Language Server
• coc-yaml for yaml
• coc-pyls for python, use Python Language Server
• coc-highlight provide default document symbol highlight and colors support.
• coc-emmet provide emmet suggest in completion list.
• coc-snippets provide snippets solution.

And more, to get full list of coc extensions, search coc.nvim on npm.

Note: use :CocConfig to edit configuration file, auto completion is supported after coc-json installed.

Example vim configuration

" if hidden not set, TextEdit might fail.
set hidden

" Better display for messages
set cmdheight=2

" Smaller updatetime for CursorHold & CursorHoldI
set updatetime=300

" don't give |ins-completion-menu| messages.
set shortmess+=c

" always show signcolumns
set signcolumn=yes

" Use tab for trigger completion with characters ahead and navigate.
" Use command ':verbose imap <tab>' to make sure tab is not mapped by other plugin.
inoremap <silent><expr> <TAB>
      \ pumvisible() ? "\<C-n>" :
      \ <SID>check_back_space() ? "\<TAB>" :
      \ coc#refresh()
inoremap <expr><S-TAB> pumvisible() ? "\<C-p>" : "\<C-h>"

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

" Use <c-space> for trigger completion.
inoremap <silent><expr> <c-space> coc#refresh()

" Use <cr> for confirm completion, `<C-g>u` means break undo chain at current position.
" Coc only does snippet and additional edit on confirm.
inoremap <expr> <cr> pumvisible() ? "\<C-y>" : "\<C-g>u\<CR>"

" Use `[c` and `]c` for navigate diagnostics
nmap <silent> [c <Plug>(coc-diagnostic-prev)
nmap <silent> ]c <Plug>(coc-diagnostic-next)

" Remap keys for gotos
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 for show documentation in preview window
nnoremap <silent> K :call <SID>show_documentation()<CR>

function! s:show_documentation()
  if &filetype == 'vim'
    execute 'h '.expand('<cword>')
  else
    call CocAction('doHover')
  endif
endfunction

" Highlight symbol under cursor on CursorHold
autocmd CursorHold * silent call CocActionAsync('highlight')

" Remap for rename current word
nmap <leader>rn <Plug>(coc-rename)

" Remap for format selected region
vmap <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

" Remap for do codeAction of selected region, ex: `<leader>aap` for current paragraph
vmap <leader>a  <Plug>(coc-codeaction-selected)
nmap <leader>a  <Plug>(coc-codeaction-selected)

" Remap for do codeAction of current line
nmap <leader>ac  <Plug>(coc-codeaction)
" Fix autofix problem of current line
nmap <leader>qf  <Plug>(coc-fix-current)

" Use `:Format` for format current buffer
command! -nargs=0 Format :call CocAction('format')

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


" Add diagnostic info for https://github.com/itchyny/lightline.vim
let g:lightline = {
      \ 'colorscheme': 'wombat',
      \ 'active': {
      \   'left': [ [ 'mode', 'paste' ],
      \             [ 'cocstatus', 'readonly', 'filename', 'modified' ] ]
      \ },
      \ 'component_function': {
      \   'cocstatus': 'coc#status'
      \ },
      \ }



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

Feedback

• If you think it's useful, give it a star.

• If you have a question, ask at gitter.

• If something not working, create a issue.

• If you want to help, but don't have time, consider donate to neovim or sponsor vim.

LICENSE