Completion with sources

Coc has full featured support for completion with LSP and doesn't bother with vim's completeopt.

Trigger mode of the completion

COC has 3 different trigger modes:

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

You can change the trigger mode by using the configuration file and change this value like:

"suggest.autoTrigger": "trigger"

To support completion trigger on inserting enter, add

"suggest.triggerAfterInsertEnter": true

to your coc-settings.json. To change the completion timeout, use:

"suggest.timeout": 500,

To make the 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": "►"

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: \<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>"

• 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
• coc-neco
• coc-snippets
• coc-neoinclude