deoplete
~ The dark powered auto
completion plugin for neovim ~
Presented by Shougo

Introduction
● This slide is English for the foreign people
● But the talk is Japanese for the Japanese
people
● The slide may contain spiritual topic or
Chuunibyou( 厨二病 )
● These are feature

Self-introduction
● Shougo
● I am called as “ 暗黒美夢王” .
● Pronounces it “Uncock Vim Awe”.
● Some people call me as “the sith lord of Vim
plugins”.
● Text editor is all of my life
● My previous works: neocomplete,
neobundle, neosnippet, unite, vimfiler,
vimshell, etc...

Today's topic
● Deoplete plugin
https://github.com/Shougo/deoplete.nvim
● It is the first asynchronous completion plugin
for neovim
● You don't have to be annoying the completion
blocks!
● If you don't know about neovim, please read
my previous presentation.
http://www.slideshare.net/Shougo/lets-talk-about-
neovim

Why deoplete is created?
● My most concern is to block Vim in the
completion
● if_lua is faster than VimL. But it also blocks
● Tarruda(neovim founder) said
Wow!!
Note: It is free translation

But
● The hell has been started from
here...

Needed works (1/4)
● Python3 support
– No if_lua support in neovim yet
– I don't want to create new
Python2 plugin in 2015
– I have added if_python3 feature
based on if_python2 in neovim
– Thanks the neovim reviewers!

Needed works (2/4)
● complete() bug fix
– It is needed for deoplete, but it is
not tested well
– Thanks the vim-jp and neovim
reviewers!

Needed works (3/4)
● v:completed_item and
completeopt patches
– It is needed for auto completion
plugins
– Thanks the vim-jp and neovim
reviewers!

Needed works (4/4)
● Understand remote plugin
features
– Less documentation
– Less examples
– Hard to debug

Deoplete original features (1/3)
● Asynchronous call omnifunc
– But the omnifunc which move
cursors(side effect) is not
supported
– For example: htmlcomplete
– Synchronous call omnifunc is
also available like neocomplete

Deoplete original features (2/3)
● Python3 sources instead of VimL
– You don't have to write VimL
– You can wrap VimL functions in
the source

Deoplete original features (3/3)
● Better buffer source
– You don't have to know the line is
cached if it is not large files
– The lines are analyzed like built-in
buffer completion
– You must wait to complete in
editing large files, but it is non
blocking!

Sources
● Built-in
– buffer, tag, file, omni, member,
dictionary
● External
– Neco-ghc, neosnippet, neco-
look, neco-vim, neco-syntax,
vim-racer, vimshell

Installation
1.Clone Deoplete source
$ git clone https://github.com/Shougo/deoplete.nvim
2.Install neovim
$ git clone https://github.com/neovim/neovim
3.Install neovim-python3
$ (sudo) pip3 install neovim

Demo
● Edit eval.c (22000 lines) with
deoplete + neovim
● Edit eval.c (22000 lines) with
neocomplete + Vim
● “Behold Vimmers, this is THE real
asynchronous!”

FAQ (1)
● Is Deoplete is faster than neocomplete?
● I think neocomplete is faster because of
if_lua power
● The asynchronous is to skip the completion
if your input is too fast
● So, you should use deoplete in newer
machine

FAQ (2)
● Deoplete does support any of languages?
● Deoplete can call omnifunc automatically
● Or you can create the source for it
● Why don't you create the source?
● :help deoplete-create-source

In the future
● Deoplete version 1.0 will be released after
the presentation!
● After version 1.0:
– More customization
– Improve file source behavior
– Implement more features in neocomplete
● Rewrite unite.vim for neovim(VimConf2016
presentation)

Fin
● If you think “Deoplete is nice!”, please
support neovim project by money or code.
https://salt.bountysource.com/teams/neovi
m
https://github.com/neovim/neovim/issues
● Deoplete depends on the neovim's
features!