Provide async autocompletion for vim8 and neovim with timers. This repository is fork of https://github.com/roxma/nvim-complete-manager in pure vim script with python dependency removed.

Installing

Plug 'prabirshrestha/asyncomplete.vim'

Tab completion

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

Force refresh completion

imap <c-space> <Plug>(asyncomplete_force_refresh)

By default asyncomplete will automatically show the autocomplete popup menu as you start typing. If you would like to disable the default behvior set g:asyncomplete_auto_popup to 0.

let g:asyncomplete_auto_popup = 0

You can use the above <Plug>(asyncomplete_force_refresh) to show the popup or can you tab to show the autocomplete.

let g:asyncomplete_auto_popup = 0

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>" :
  \ asyncomplete#force_refresh()
inoremap <expr><S-TAB> pumvisible() ? "\<C-p>" : "\<C-h>"

Remove duplicates

If you have many sources enabled (especially the buffer source), it might be useful to remove duplicates from the completion list. You can enable this by setting g:asyncomplete_remove_duplicates to 1.

let g:asyncomplete_remove_duplicates = 1

Preview Window

To disable preview window:

set completeopt-=preview

To enable preview window:

set completeopt+=preview

To auto close preview window when completion is done.

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

Sources

asyncomplete.vim deliberately does not contain any sources. Please use one of the following sources or create your own.

Language Server Protocol (LSP)

Language Server Protocol via vim-lsp and asyncomplete-lsp.vim

Plug 'prabirshrestha/asyncomplete.vim'
Plug 'prabirshrestha/async.vim'
Plug 'prabirshrestha/vim-lsp'
Plug 'prabirshrestha/asyncomplete-lsp.vim'

if executable('pyls')
    " pip install python-language-server
    au User lsp_setup call lsp#register_server({
        \ 'name': 'pyls',
        \ 'cmd': {server_info->['pyls']},
        \ 'whitelist': ['python'],
        \ })
endif

Refer to vim-lsp wiki for configuring other language servers. Besides auto-complete language server support other features such as go to definition, find references, renaming symbols, document symbols, find workspace symbols, formatting and so on.

in alphabetical order

Languages/FileType/Source	Links
Buffer	asyncomplete-buffer.vim
Emoji	asyncomplete-emoji.vim
Go	asyncomplete-gocode.vim
JavaScript (Flow)	asyncomplete-flow.vim
Omni	asyncomplete-omni.vim
Racer	asyncomplete-racer.vim
Typescript	asyncomplete-tscompletejob.vim
Vim Syntax	asyncomplete-necosyntax.vim
Vim	asyncomplete-necovim.vim
Neosnippet	asyncomplete-neosnippet.vim
UltiSnips	asyncomplete-ultisnips.vim
vim tags	asyncomplete-tags.vim

can't find what you are looking for? write one instead an send a PR to be included here

Priority

Use priority to control the order of the source. Highest priority comes first. priority is optional and defaults to 0 when registering a source.

Example

function! s:js_completor(opt, ctx) abort
    let l:col = a:ctx['col']
    let l:typed = a:ctx['typed']

    let l:kw = matchstr(l:typed, '\v\S+$')
    let l:kwlen = len(l:kw)

    let l:startcol = l:col - l:kwlen

    let l:matches = [
        \ "do", "if", "in", "for", "let", "new", "try", "var", "case", "else", "enum", "eval", "null", "this", "true",
        \ "void", "with", "await", "break", "catch", "class", "const", "false", "super", "throw", "while", "yield",
        \ "delete", "export", "import", "public", "return", "static", "switch", "typeof", "default", "extends",
        \ "finally", "package", "private", "continue", "debugger", "function", "arguments", "interface", "protected",
        \ "implements", "instanceof"
        \ ]

    call asyncomplete#complete(a:opt['name'], a:ctx, l:startcol, l:matches)
endfunction

au User asyncomplete_setup call asyncomplete#register_source({
    \ 'name': 'javascript',
    \ 'whitelist': ['javascript'],
    \ 'priority': 5,
    \ 'completor': function('s:js_completor'),
    \ })

The above sample shows synchronous completion. If you would like to make it async just call asyncomplete#complete whenever you have the results ready.

call timer_start(2000, {timer-> asyncomplete#complete(a:opt['name'], a:ctx, l:startcol, l:matches)})

If you are returning incomplete results and would like to trigger completion on the next keypress pass 1 as the fifth parameter to asyncomplete#complete which signifies the result is incomplete.

call asyncomplete#complete(a:opt['name'], a:ctx, l:startcol, l:matches, 1)

As a source author you do not have to worry about synchronization issues in case the server returns the async completion after the user has typed more characters. asyncomplete.vim uses partial caching as well as ignores if the context changes when calling asyncomplete#complete. This is one of the core reason why the original context must be passed when calling asyncomplete#complete.

Credits

All the credit goes to the following projects

README.md

asyncomplete.vim