Async Language Server Protocol plugin for vim8 and neovim.

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

Note: async.vim is required and is used to normalize jobs between vim8 and neovim.

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

function! s:on_lsp_buffer_enabled() abort
    setlocal omnifunc=lsp#complete
    setlocal signcolumn=yes
    nmap <buffer> gd <plug>(lsp-definition)
    nmap <buffer> <f2> <plug>(lsp-rename)
    " refer to doc to add more commands
endfunction

augroup lsp_install
    au!
    " call s:on_lsp_buffer_enabled only for languages that has the server registered.
    autocmd User lsp_buffer_enabled call s:on_lsp_buffer_enabled()
augroup END

Refer to vim-lsp-settings on how to easily setup language servers using vim-lsp automatically.

Plug 'prabirshrestha/async.vim'
Plug 'prabirshrestha/vim-lsp'
Plug 'mattn/vim-lsp-settings'

Refer to docs on configuring omnifunc or asyncomplete.vim.

vim-lsp does not support snippets by default. If you want snippet integration, you will first have to install a third-party snippet plugin and a plugin that integrates it in vim-lsp. At the moment, you have following options:

1. vim-vsnip together with vim-vsnip-integ
2. UltiSnips together with vim-lsp-ultisnips
3. neosnippet.vim together with vim-lsp-neosnippet

For more information, refer to the readme and documentation of the respective plugins.

You can let the language server automatically handle folding for you. To enable this, you have to set 'foldmethod', 'foldexpr' and (optionally) 'foldtext':

set foldmethod=expr
  \ foldexpr=lsp#ui#vim#folding#foldexpr()
  \ foldtext=lsp#ui#vim#folding#foldtext()

If you would like to disable folding globally, you can add this to your configuration:

let g:lsp_fold_enabled = 0

Also see :h vim-lsp-folding.

vim-lsp supports the unofficial extension to the LSP protocol for semantic highlighting (microsoft/vscode-languageserver-node#367). This feature requires Neovim highlights, or Vim with the textprop feature enabled. You will also need to link language server semantic scopes to Vim highlight groups. Refer to :h vim-lsp-semantic for more info.

Note:

• Some servers may only support partial commands.
• While it is possible to register multiple servers for the same filetype, some commands will pick only the first server that supports it. For example, it doesn't make sense for rename and format commands to be sent to multiple servers.

Document diagnostics (e.g. warnings, errors) are enabled by default, but if you preferred to turn them off and use other plugins instead (like Neomake or ALE, set g:lsp_diagnostics_enabled to 0:

let g:lsp_diagnostics_enabled = 0         " disable diagnostics support

let g:lsp_signs_enabled = 1         " enable signs
let g:lsp_diagnostics_echo_cursor = 1 " enable echo under cursor when in normal mode

Four groups of signs are defined and used: LspError, LspWarning, LspInformation, LspHint. It is possible to set custom text or icon that will be used for each sign (note that icons are only available in GUI). To do this, set some of the following globals: g:lsp_signs_error, g:lsp_signs_warning, g:lsp_signs_information, g:lsp_signs_hint. They should be set to a dict, that contains either text that will be used as sign in terminal, or icon that will be used for GUI, or both. For example:

let g:lsp_signs_error = {'text': '✗'}
let g:lsp_signs_warning = {'text': '‼', 'icon': '/path/to/some/icon'} " icons require GUI
let g:lsp_signs_hint = {'icon': '/path/to/some/other/icon'} " icons require GUI

Also three highlight groups for every sign group are defined (for example for LspError these are LspErrorText, LspErrorVirtual, and LspErrorHighlight). By default, LspError text is highlighted using Error group, LspWarning is highlighted as Todo, others use Normal group. Virtual text will by default use the Text highlight group, for example for LspErrorVirtual will default to LspErrorText. Line highlighting is not set by default. If your colorscheme of choice does not provide any of these, it is possible to clear them or link to some other group, like so:

highlight link LspErrorText GruvboxRedSign " requires gruvbox
highlight clear LspWarningLine

Highlighting diagnostics requires either NeoVim 0.3+ or Vim with patch 8.1.0579. They are enabled by default when supported, but can be turned off respectively by

let g:lsp_highlights_enabled = 0
let g:lsp_textprop_enabled = 0

Can be customized by setting or linking LspErrorHighlight, LspWarningHighlight, LspInformationHighlight and LspHintHighlight highlight groups.

In NeoVim 0.3 or newer you can use virtual text feature (enabled by default). You can disable it by adding

let g:lsp_virtual_text_enabled = 0

To your configuration.

Virtual text will use the same highlight groups as signs feature.

Highlight references to the symbol under the cursor. To enable, set in your configuration:

let g:lsp_highlight_references_enabled = 1

To change the style of the highlighting, you can set or link the lspReference highlight group, e.g.:

highlight lspReference ctermfg=red guifg=red ctermbg=green guibg=green

In order to enable file logging set g:lsp_log_file.

let g:lsp_log_verbose = 1
let g:lsp_log_file = expand('~/vim-lsp.log')

" for asyncomplete.vim log
let g:asyncomplete_log_file = expand('~/asyncomplete.log')