diff --git a/after/ftplugin/haskell.vim b/after/ftplugin/haskell.vim
index 2481eaa..124d675 100644
--- a/after/ftplugin/haskell.vim
+++ b/after/ftplugin/haskell.vim
@@ -15,7 +15,7 @@ map <leader>ctg :codex<CR>
 set tags=tags;/,codex.tags;/
 
 " classic ctags jump
-nnoremap <leader>gd <C-]>
+" nnoremap <leader>gd <C-]>
 
 nnoremap <silent> <leader>cgd :cs find g <C-R>=expand("<cword>")<CR><CR>
 nnoremap <silent> <C-\> :cs find c <C-R>=expand("<cword>")<CR><CR>
@@ -96,26 +96,33 @@ let g:vim_annotations_offset = '/.liquid/'
 " LSP
 let g:LanguageClient_autoStart = 0
 let g:LanguageClient_serverCommands = {
-	\ 'haskell': ['hie-wrapper', '--lsp', '-d', '-l', $HOME.'/lang-server.log'],
+	\ 'haskell': ['hie-wrapper', '--lsp', '-d', '-l', $HOME.'/lang-server-lnvim.log'],
 	\ }
 " we use ALE instead
 let g:LanguageClient_diagnosticsEnable = 0
 
-nnoremap <leader>lc :call LanguageClient_contextMenu()<CR>
-" nnoremap <silent> gd :call LanguageClient#textDocument_definition()<CR>
-nnoremap <silent> <C-F6> :call LanguageClient#textDocument_hover()<CR>
-vnoremap <silent> <C-F6> :call LanguageClient#textDocument_hover()<CR>
-nnoremap <silent> <C-F8> :call LanguageClient#textDocument_rename()<CR>
+" nnoremap <leader>ld :call LanguageClient#textDocument_definition()<CR>
+" nnoremap <leader>lr :call LanguageClient#textDocument_rename()<CR>
+" nnoremap <leader>lf :call LanguageClient#textDocument_formatting()<CR>
+" nnoremap <leader>lt :call LanguageClient#textDocument_typeDefinition()<CR>
+" nnoremap <leader>lx :call LanguageClient#textDocument_references()<CR>
+" nnoremap <leader>la :call LanguageClient_workspace_applyEdit()<CR>
+" nnoremap <leader>lc :call LanguageClient#textDocument_completion()<CR>
+" nnoremap <leader>lh :call LanguageClient#textDocument_hover()<CR>
+" nnoremap <leader>ls :call LanguageClient_textDocument_documentSymbol()<CR>
+" nnoremap <leader>lm :call LanguageClient_contextMenu()<CR>
+" nnoremap <F6> :call LanguageClient#textDocument_hover()<CR>
+
 
 " deoplete
-call deoplete#custom#option('sources',{
-	\ '_': ['buffer'],
-	\ 'haskell': ['neosnippet', 'buffer', 'file', 'neco-ghc']
-	\ })
-	" \ 'haskell': ['neosnippet', 'buffer', 'file', 'neco-ghc']
-" inoremap <expr><tab> pumvisible() ? "\<c-n>" : "\<tab>"
-call deoplete#enable()
-call deoplete#enable_logging('DEBUG', $HOME . '/deoplete.log')
+"call deoplete#custom#option('sources',{
+"	\ '_': ['buffer'],
+"	\ 'haskell': ['neosnippet', 'buffer', 'file', 'neco-ghc']
+"	\ })
+"	" \ 'haskell': ['neosnippet', 'buffer', 'file', 'neco-ghc']
+"call deoplete#enable()
+"call deoplete#enable_logging('DEBUG', $HOME . '/deoplete.log')
+"" inoremap <expr><tab> pumvisible() ? "\<c-n>" : "\<tab>"
 
 let g:ghcmod_hlint_options = ['--ignore=Eta reduce $']
 
@@ -139,17 +146,18 @@ let g:ale_haskell_argon_info_level = 6
 " autocmd FileType haskell setlocal omnifunc=necoghc#omnifunc
 " let g:ycm_semantic_triggers = {'haskell' : ['.']}
 
+" let g:ycm_language_server = [ { 'name': 'haskell', 'filetypes': [ 'haskell', 'hs', 'lhs' ], 'cmdline': [ 'hie-wrapper' ], 'project_root_files': [ '.stack.yaml', 'cabal.config', 'package.yaml', 'cabal.project' ] } ]
 
 
 
 " clear search
-nmap <F2> :noh<CR>:GhcModTypeClear<CR>
-imap <F2> <C-O>:noh<CR>:GhcModTypeClear<CR>
+" nmap <F2> :noh<CR>:GhcModTypeClear<CR>
+" imap <F2> <C-O>:noh<CR>:GhcModTypeClear<CR>
 
 " unmap <F3>
 " unmap <F4>
 
-nmap <F6> :GhcModType<CR>
+" nmap <F6> :GhcModType<CR>
 
 " for intero
 " if has("nvim")
@@ -188,3 +196,139 @@ let g:neoformat_enabled_haskell = ['brittany']
 	" nnoremap <silent> <leader>it :InteroTypeInsert<CR>
 	" nnoremap <leader>ist :InteroSetTargets<SPACE>
 " endif
+
+
+
+
+" ============ coc.nvim ===========
+" markdown rendering of code blocks
+let g:markdown_fenced_languages = ['haskell']
+
+" if hidden is not set, TextEdit might fail.
+set hidden
+
+" Some servers have issues with backup files, see #649
+set nobackup
+set nowritebackup
+
+" Better display for messages
+"set cmdheight=2
+
+" You will have bad experience for diagnostic messages when it's default 4000.
+set updatetime=300
+
+" don't give |ins-completion-menu| messages.
+set shortmess+=c
+
+" always show signcolumns
+set signcolumn=yes
+
+" Use tab for trigger completion with characters ahead and navigate.
+" Use command ':verbose imap <tab>' to make sure tab is not mapped by other plugin.
+inoremap <silent><expr> <TAB>
+      \ pumvisible() ? "\<C-n>" :
+      \ <SID>check_back_space() ? "\<TAB>" :
+      \ coc#refresh()
+inoremap <expr><S-TAB> pumvisible() ? "\<C-p>" : "\<C-h>"
+
+function! s:check_back_space() abort
+  let col = col('.') - 1
+  return !col || getline('.')[col - 1]  =~# '\s'
+endfunction
+
+" Use <c-space> to trigger completion.
+inoremap <silent><expr> <c-space> coc#refresh()
+
+" Use <cr> to confirm completion, `<C-g>u` means break undo chain at current position.
+" Coc only does snippet and additional edit on confirm.
+inoremap <expr> <cr> pumvisible() ? "\<C-y>" : "\<C-g>u\<CR>"
+" Or use `complete_info` if your vim support it, like:
+" inoremap <expr> <cr> complete_info()["selected"] != "-1" ? "\<C-y>" : "\<C-g>u\<CR>"
+
+" Use `[g` and `]g` to navigate diagnostics
+nmap <silent> [g <Plug>(coc-diagnostic-prev)
+nmap <silent> ]g <Plug>(coc-diagnostic-next)
+
+" Remap keys for gotos
+nmap <silent> gd <Plug>(coc-definition)
+nmap <silent> gy <Plug>(coc-type-definition)
+nmap <silent> gi <Plug>(coc-implementation)
+nmap <silent> gr <Plug>(coc-references)
+
+" Use K to show documentation in preview window
+nnoremap <silent> K :call <SID>show_documentation()<CR>
+
+function! s:show_documentation()
+  if (index(['vim','help'], &filetype) >= 0)
+    execute 'h '.expand('<cword>')
+  else
+    call CocAction('doHover')
+  endif
+endfunction
+
+" Highlight symbol under cursor on CursorHold
+autocmd CursorHold * silent call CocActionAsync('highlight')
+
+" Remap for rename current word
+nmap <leader>rn <Plug>(coc-rename)
+
+" Remap for format selected region
+xmap <leader>f  <Plug>(coc-format-selected)
+nmap <leader>f  <Plug>(coc-format-selected)
+
+augroup mygroup
+  autocmd!
+  " Setup formatexpr specified filetype(s).
+  autocmd FileType typescript,json setl formatexpr=CocAction('formatSelected')
+  " Update signature help on jump placeholder
+  autocmd User CocJumpPlaceholder call CocActionAsync('showSignatureHelp')
+augroup end
+
+" Remap for do codeAction of selected region, ex: `<leader>aap` for current paragraph
+xmap <leader>a  <Plug>(coc-codeaction-selected)
+nmap <leader>a  <Plug>(coc-codeaction-selected)
+
+" Remap for do codeAction of current line
+nmap <leader>ac  <Plug>(coc-codeaction)
+" Fix autofix problem of current line
+nmap <leader>qf  <Plug>(coc-fix-current)
+
+" Create mappings for function text object, requires document symbols feature of languageserver.
+xmap if <Plug>(coc-funcobj-i)
+xmap af <Plug>(coc-funcobj-a)
+omap if <Plug>(coc-funcobj-i)
+omap af <Plug>(coc-funcobj-a)
+
+" Use <TAB> for select selections ranges, needs server support, like: coc-tsserver, coc-python
+nmap <silent> <TAB> <Plug>(coc-range-select)
+xmap <silent> <TAB> <Plug>(coc-range-select)
+
+" Use `:Format` to format current buffer
+command! -nargs=0 Format :call CocAction('format')
+
+" Use `:Fold` to fold current buffer
+command! -nargs=? Fold :call     CocAction('fold', <f-args>)
+
+" use `:OR` for organize import of current buffer
+command! -nargs=0 OR   :call     CocAction('runCommand', 'editor.action.organizeImport')
+
+" Add status line support, for integration with other plugin, checkout `:h coc-status`
+set statusline^=%{coc#status()}%{get(b:,'coc_current_function','')}
+
+" Using CocList
+" Show all diagnostics
+nnoremap <silent> <space>a  :<C-u>CocList diagnostics<cr>
+" Manage extensions
+nnoremap <silent> <space>e  :<C-u>CocList extensions<cr>
+" Show commands
+nnoremap <silent> <space>c  :<C-u>CocList commands<cr>
+" Find symbol of current document
+nnoremap <silent> <space>o  :<C-u>CocList outline<cr>
+" Search workspace symbols
+nnoremap <silent> <space>s  :<C-u>CocList -I symbols<cr>
+" Do default action for next item.
+nnoremap <silent> <space>j  :<C-u>CocNext<CR>
+" Do default action for previous item.
+nnoremap <silent> <space>k  :<C-u>CocPrev<CR>
+" Resume latest coc list
+nnoremap <silent> <space>p  :<C-u>CocListResume<CR>
diff --git a/coc-settings.json b/coc-settings.json
new file mode 100644
index 0000000..55bc38c
--- /dev/null
+++ b/coc-settings.json
@@ -0,0 +1,27 @@
+{
+  "languageserver": {
+    "haskell": {
+      "trace.server": "verbose",
+      "command": "hie-wrapper",
+      "args": ["--lsp", "-d", "-l", "/home/jule/lang-server.log"],
+      "rootPatterns": [
+        "stack.yaml",
+        "cabal.config",
+        "cabal.project",
+        "package.yaml"
+      ],
+      "filetypes": [
+        "hs",
+        "lhs",
+        "haskell"
+      ],
+      "initializationOptions": {
+        "languageServerHaskell": {
+          "hlintOn": false
+        }
+      }
+    }
+  },
+  "coc.preferences.hoverTarget": "preview",
+  "suggest.floatEnable": true
+}
diff --git a/vimrc b/vimrc
index 9dec29c..45fff0a 100644
--- a/vimrc
+++ b/vimrc
@@ -53,17 +53,17 @@ Plug 'LucHermitte/lh-vim-lib'
 Plug 'LucHermitte/local_vimrc'
 
 " completion
-" Plug 'Valloric/YouCompleteMe', { 'do': './install.py --clang-completer --go-completer --rust-completer --system-boost --system-libclang',
-    " \ 'for': ['c', 'python', 'sh', 'go', 'clojure'],
-    " \ }
+Plug 'Valloric/YouCompleteMe', { 'do': './install.py --clang-completer --go-completer --rust-completer --system-boost --system-libclang',
+    \ 'for': ['c', 'python', 'sh', 'go', 'clojure'],
+    \ }
 " deoplete for haskell
 if has('nvim')
-  Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins',
-			  \ }
+  " Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins',
+			  " \ }
 else
-  Plug 'Shougo/deoplete.nvim'
-  Plug 'roxma/nvim-yarp'
-  Plug 'roxma/vim-hug-neovim-rpc'
+  " Plug 'Shougo/deoplete.nvim'
+  " Plug 'roxma/nvim-yarp'
+  " Plug 'roxma/vim-hug-neovim-rpc'
 endif
 
 " snippets
@@ -72,10 +72,24 @@ Plug 'honza/vim-snippets'
 
 " LSP
 " setting this per-language breaks "let g:LanguageClient_autoStart = 1",
-Plug 'autozimu/LanguageClient-neovim', {
-	\ 'branch': 'next',
-	\ 'do': 'bash install.sh',
-	\ }
+" Plug 'autozimu/LanguageClient-neovim', {
+	" \ 'branch': 'next',
+	" \ 'do': 'bash install.sh',
+	" \ }
+
+" Use release branch (Recommend)
+Plug 'neoclide/coc.nvim', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-tsserver', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-git', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-rls', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-prettier', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-python', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+"Plug 'neoclide/coc-vetur', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-json', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-eslint', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-yaml', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-highlight', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
+Plug 'neoclide/coc-json', {'do': 'yarn install --frozen-lockfile', 'for': ['haskell']}
 
 " linting/compilation
 Plug 'w0rp/ale', {