Add coc - completion framework support

README.md

@@ -1,4 +1,4 @@
-# Using NeoVim as an Python+Go IDE
+# Using NeoVim as an Python+Golang IDE
 
 [Neovim](https://neovim.io/) is a pretty cool successor to Vim, focusing on compatibility while adding asynchronous plugin functionality and trying to clean up the code base. Having been fed up at various times with both Sublime Text (2 and 3) and Atom, and after realizing how much development I do over SSH, it seemed reasonable to check out using vim (or nvim, in this case) as my IDE. The advantages essentially boil down to:
 
@@ -34,7 +34,9 @@ Complete instructions to Neovim as your IDE - Inspired by [Jarol Rodriguez's vim
   $ sudo -H pip3 install powerline-status
   ```
 
-4. Clone init.vim - neovim configuration file to specific path, in this case is `~/.config/nvim/init.vim`:
+4. To use [coc](https://github.com/neoclide/coc.nvim), you have to configure the [Lauguage servers](https://github.com/neoclide/coc.nvim/wiki/Language-servers) also. 
+
+5. Clone init.vim - neovim configuration file to specific path, in this case is `~/.config/nvim/init.vim`:
 
   ```
   $ cd ~/.config/nvim/

init.vim

@@ -30,6 +30,7 @@ Plug 'majutsushi/tagbar'                  " Class/module browser
 Plug 'bling/vim-bufferline'               " Buffer-line vim - show list of buffers in command bar
 Plug 'junegunn/limelight.vim'             " Hyperfocus-writing in Vim
 Plug 'brooth/far.vim'                     " Find and replace
+Plug 'neoclide/coc.nvim', {'tag': '*', 'branch': 'release'} "An intellisense engine
 
 "-------------------=== Fancy things ===----------------------------
 Plug 'flazz/vim-colorschemes'             " Colorschemes
@@ -396,3 +397,71 @@ if executable('ag')
 endif
 
 let g:go_version_warning = 0
+
+" -----
+"  COC
+" -----
+
+" Better display for messages
+set cmdheight=2
+" Smaller updatetime for CursorHold & CursorHoldI
+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 `[c` and `]c` to navigate diagnostics
+nmap <silent> [c <Plug>(coc-diagnostic-prev)
+nmap <silent> ]c <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 U to show documentation in preview window
+nnoremap <silent> U :call <SID>show_documentation()<CR>
+
+" Remap for rename current word
+nmap <leader>rn <Plug>(coc-rename)
+
+" Remap for format selected region
+vmap <leader>f  <Plug>(coc-format-selected)
+nmap <leader>f  <Plug>(coc-format-selected)
+" 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>
+
+" disable vim-go :GoDef short cut (gd)
+" this is handled by LanguageClient [LC]
+let g:go_def_mapping_enabled = 0