Completion with sources

Coc.nvim has full support for LSP completion, including snippet and additional text edits support.

By default, coc.nvim use its own completeopt option during completion to provide the best auto completion experience.

There's no function can be used as omnifunc option provided from coc.nvim since it's not possible to support all LSP completion features when using omnifunc option.

Trigger mode of the completion

There're 3 different trigger modes:

• always, the default mode, which triggers completion on a word letter inserted and triggerCharacters (or trigger pattern match) defined by the current activated sources.
• trigger, only trigger completion when you type triggerCharacters (or trigger pattern match) defined by the completion sources.
• none, disable auto trigger completion, you will have to trigger the completion manually.

Some completion behavior can be changed by using the configuration file.

To change the trigger mode, add:

"suggest.autoTrigger": "trigger"

To support completion trigger on insert enter, add

"suggest.triggerAfterInsertEnter": true

To change the completion timeout, use:

"suggest.timeout": 500,

To make the completion automatically select the first completed item, use:

"suggest.noselect": false,

To make the completion trigger with two input characters, use:

"suggest.minTriggerInputLength": 2

To enable the commit characters feature, use:

"suggest.acceptSuggestionOnCommitCharacter": true

To change the indicator of snippet items, use:

"suggest.snippetIndicator": "►"

To get the full list checkout the help by :h coc-configuration in your vim.

Use <Tab> or custom key for trigger completion

You can make use of coc#refresh() for trigger completion like this:

" use <tab> for trigger completion and navigate to the next complete item
function! s:check_back_space() abort
  let col = col('.') - 1
  return !col || getline('.')[col - 1]  =~ '\s'
endfunction

inoremap <silent><expr> <Tab>
      \ pumvisible() ? "\<C-n>" :
      \ <SID>check_back_space() ? "\<Tab>" :
      \ coc#refresh()

Note: the <tab> could be remapped by another plugin, use :verbose imap <tab> to check if it's mapped as expected.

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

Improve the completion experience

• Use <Tab> and <S-Tab> to navigate the completion list:

  inoremap <expr> <Tab> pumvisible() ? "\<C-n>" : "\<Tab>"
  inoremap <expr> <S-Tab> pumvisible() ? "\<C-p>" : "\<S-Tab>"

• Use <cr> to confirm completion

  inoremap <expr> <cr> pumvisible() ? "\<C-y>" : "\<C-g>u\<CR>"

  Note: you have to remap <cr> to make sure it confirm completion when pum is visible.

  Note: \<C-g>u is used to break undo level.

  To make <cr> select the first completion item and confirm the completion when no item has been selected:

  inoremap <silent><expr> <cr> pumvisible() ? coc#_select_confirm() : "\<C-g>u\<CR>"

  To make coc.nvim format your code on <cr>, use keymap:

  inoremap <silent><expr> <cr> pumvisible() ? coc#_select_confirm() : "\<C-g>u\<CR>\<c-r>=coc#on_enter()\<CR>"

• Close the preview window when completion is done.

  autocmd! CompleteDone * if pumvisible() == 0 | pclose | endif

Completion sources

Bundled sources.

Name	Shortcut	Description
around	[A]	Words of the current buffer.
buffer	[B]	Words of none current buffer.
file	[F]	Filename completion, auto detected.

Configuring sources

You can configure completion sources by using coc-settings.json

• "coc.source.{name}.enable": controls if the source is enabled.
• "coc.source.{name}.shortcut": shortcut used in completion menu.
• "coc.source.{name}.priority": priority of the source, lower priority sources will be sorted after high priority sources when they have same score.
• "coc.source.{name}.disableSyntaxes": syntax names used to disable source from completion, eg: ["comment", "string"]

More sources

• coc-sources: includes some common completion source extensions.
• coc-neco: viml completion support.
• coc-snippets: snippets solution for coc.nvim
• coc-vimtex: vimtex integration.
• coc-neoinclude: neoinclude integration.
• coc-lbdbq: email address completion.
• coc-browser: web browser words completion.