Use vim-lsp instead of ale

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()