completion-nvim

completion-nvim is a auto completion framework aims to provide a better completion experience with neovim's built-in LSP. Other LSP sources is not supported.

Features

Asynchronous completion using libuv api.
Automatically open hover windows when popupmenu is available.
Automatically open signature help if it's available.
Snippets integration with UltiSnips and Neosnippet.
Chain completion support inspired by

Demo

Demo using sumneko_lua

Prerequisite

Neovim nightly
You should be setting up language server with the help of nvim-lsp

Install

Install with any plugin manager by using the path on GitHub.

Plug 'haorenW1025/completion-nvim'

Setup

completion-nvim require several autocommand set up to work properly, you should set it up using the on_attach function like this.
```
lua require'nvim_lsp'.pyls.setup{on_attach=require'completion'.on_attach}
```
Change pyls to whatever language server you are using.
If you want completion-nvim to set up all buffer instead of only used it when lsp is enable, call the on_attach function directly, for example

" Use completion-nvim in every buffer
autocmd BufEnter * lua require'completion'.on_attach()

NOTE It's okay to set up completion-nvim without lsp. It will simply use other completion source instead(Ex: snippets).

Configuration

Recommended Setting

" Use <Tab> and <S-Tab> to navigate through popup menu
inoremap <expr> <Tab>   pumvisible() ? "\<C-n>" : "\<Tab>"
inoremap <expr> <S-Tab> pumvisible() ? "\<C-p>" : "\<S-Tab>"

" Set completeopt to have a better completion experience
set completeopt=menuone,noinsert,noselect

" Avoid showing message extra message when using completion
set shortmess+=c

Enable/Disable auto popup

By default auto popup is enable, turn it off by

let g:completion_enable_auto_popup = 0

Or you can toggle auto popup on the fly by using command CompletionToggle
You can manually trigger completion with mapping key by

inoremap <silent><expr> <c-p> completion#trigger_completion() "map <c-p> to manually trigger completion

Or you want to use <Tab> as trigger keys

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>" :
  \ completion#trigger_completion()

Enable Snippets Support

By default other snippets source support are closed, turn it on by

let g:completion_enable_snippet = 'UltiSnips'

Support UltiSnips and Neosnippet

Chain Completion Support

completion-nvim support chain completion, which use other completion sources and ins-completion as fallback for lsp completion.
See for details for how to set it up.

Changing Completion Confirm key

By default <CR> is use for confirm completion and expand snippets, change it by

let g:completion_confirm_key = "\<C-y>"

Make sure to use " " and add escape key \ to avoid parsing issue.
If confirm key has a fallback mapping, for example, if you use auto pairs plugin that maps to <CR>, provide it like this:

"Fallback for https://github.com/Raimondi/delimitMate expanding on enter
let g:completion_confirm_key_rhs = "\<Plug>delimitMateCR"

Enable/Disable auto hover

By default when navigate through complete items, LSP's hover is automatically called and display in floating window, disable it by

let g:completion_enable_auto_hover = 0

Enable/Disable auto signature

By default signature help is open automatically whenever it's available, disable it by

let g:completion_enable_auto_signature = 0

Enable/Disable completion in comment

By default completion will not activate when you're in a comment section, enable it by

call completion#enable_in_comment()

Max Items for completion

You can set a number limit for the maximum completion items, for example, you just want at most 10 items in your popup menu, set it by

let g:completion_max_items = 10

Note that this only works for non ins-complete completion source.

Trigger Characters

You can add or disable trigger character that will trigger completion. By default trigger character = ['.'], you can disable it by

let g:completion_trigger_character = []

Or multiple trigger character

let g:completion_trigger_character = ['.', '::']

If you want different trigger character for different language, wrap it in an autocommand like

augroup CompleteionTriggerCharacter
    autocmd!
    autocmd BufEnter * let g:completion_trigger_character = ['.']
    autocmd BufEnter *.c,*.cpp let g:completion_trigger_character = ['.', '::']
augroup end

Trouble Shooting

This plugin is in early stage, might have unexpected issues. Please follow for trouble shooting.
Feel free to post issues on any unexpected behavior or feature request!

urandom/completion-nvim