Use vim-lsp instead of ale

ale.vim

@@ -1,17 +0,0 @@
-" Defines a specific list of linters, that you wish to use for a language
-" Install the flake8, python-pylint packages
-let g:ale_linters = {
-    \ 'python': ['flake8', 'pylint'],
-    \ 'rust': ['rls'],
-    \}
-
-let g:ale_fixers = { 
-    \ 'python': ['yapf'],
-    \ 'rust': ['rustfmt']
-    \}
-
-nmap <F10> :ALEFix<CR>
-
-let g:ale_fix_on_save = 1
-let g:airline#extensions#ale#enabled = 1
-

init.vim

@@ -70,7 +70,7 @@ source ~/.config/nvim/rainbow.vim
 source ~/.config/nvim/neomake.vim
 source ~/.config/nvim/keymap.vim
 source ~/.config/nvim/timestamp.vim
-source ~/.config/nvim/ale.vim
 source ~/.config/nvim/html.vim
+source ~/.config/nvim/vim-lsp.vim
 source ~/.config/nvim/python.vim
 source ~/.config/nvim/rust.vim

keymap.vim

@@ -23,8 +23,8 @@ noremap <A-t> :belowright split +resize12 term://zsh<CR>
 noremap <C-S-d> :bnext <CR> :bd#<CR>
 
 " Map ale wraps to control+k and control+j
-nmap <silent> <C-k> <Plug>(ale_previous_wrap)
-nmap <silent> <C-j> <Plug>(ale_next_wrap)
+nmap <silent> <C-k> <Plug>(LspPreviousDiagnostic)
+nmap <silent> <C-j> <Plug>(LspNextDiagnostic)
 
 " Map vim-grammarous to <F6>
 nmap <F6> :GrammarousCheck <CR>

plug.vim

@@ -15,6 +15,7 @@ Plug 'bling/vim-bufferline'
 Plug 'junegunn/fzf.vim'
 Plug 'tpope/vim-commentary'
 Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }
+Plug 'lighttiger2505/deoplete-vim-lsp'
 Plug 'machakann/vim-highlightedyank'
 
 " Use rainbow parenthesis and automatic closing parens
@@ -22,7 +23,8 @@ Plug 'luochen1990/rainbow'
 Plug 'jiangmiao/auto-pairs'
 
 " Linting plugin for multiple languages
-Plug 'dense-analysis/ale'
+Plug 'prabirshrestha/vim-lsp'
+Plug 'mattn/vim-lsp-settings'
 
 " Language support for LaTeX
 Plug 'vim-latex/vim-latex'

python.vim

@@ -3,3 +3,12 @@ au BufNewFile,BufRead *.py
     \ setlocal foldmethod=indent 
     \ nospell
 
+" register pyls as a language server.
+if executable('pyls')
+    " pip install python-language-server
+    au User lsp_setup call lsp#register_server({
+        \ 'name': 'pyls',
+        \ 'cmd': {server_info->['pyls']},
+        \ 'allowlist': ['python'],
+        \ })
+endif

rust.vim

@@ -1,4 +1,11 @@
 " No spell checking in code file
 autocmd BufNewFile,BufRead *.rs setlocal nospell
 
-
+if executable('rls')
+    " pip install rust-language-server
+    au User lsp_setup call lsp#register_server({
+        \ 'name': 'rls',
+        \ 'cmd': {server_info->['rls']},
+        \ 'allowlist': ['rust'],
+        \ })
+endif

vim-lsp.vim

@@ -0,0 +1,36 @@
+" Configure the vim-lsp plugin in order to register any language server.
+"
+
+function! s:on_lsp_buffer_enabled() abort
+    setlocal omnifunc=lsp#complete
+    setlocal signcolumn=yes
+    if exists('+tagfunc') | setlocal tagfunc=lsp#tagfunc | endif
+    nmap <buffer> gd <plug>(lsp-definition)
+    nmap <buffer> gs <plug>(lsp-document-symbol-search)
+    nmap <buffer> gS <plug>(lsp-workspace-symbol-search)
+    nmap <buffer> gr <plug>(lsp-references)
+    nmap <buffer> gi <plug>(lsp-implementation)
+    nmap <buffer> gt <plug>(lsp-type-definition)
+    nmap <buffer> <leader>rn <plug>(lsp-rename)
+    nmap <buffer> [g <plug>(lsp-previous-diagnostic)
+    nmap <buffer> ]g <plug>(lsp-next-diagnostic)
+    nmap <buffer> K <plug>(lsp-hover)
+    inoremap <buffer> <expr><c-f> lsp#scroll(+4)
+    inoremap <buffer> <expr><c-d> lsp#scroll(-4)
+
+    let g:lsp_format_sync_timeout = 1000
+    autocmd! BufWritePre *.rs,*.go call execute('LspDocumentFormatSync')
+    
+    " 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
+
+" Set folding
+set foldmethod=expr
+  \ foldexpr=lsp#ui#vim#folding#foldexpr()
+  \ foldtext=lsp#ui#vim#folding#foldtext()