Update get lsp omni completion items

See #18

autoload/deoplete_vim_lsp.vim

@@ -9,36 +9,33 @@ func! deoplete_vim_lsp#request(server_name, opt, ctx) abort
 endfunc
 
 function! s:completor(server_name, opt, ctx) abort
+    let l:position = lsp#get_position()
     call lsp#send_request(a:server_name, {
         \ 'method': 'textDocument/completion',
         \ 'params': {
         \   'textDocument': lsp#get_text_document_identifier(),
-        \   'position': lsp#get_position(),
+        \   'position': l:position,
         \ },
-        \ 'on_notification': function('s:handle_completion', [a:server_name, a:opt, a:ctx]),
+        \ 'on_notification': function('s:handle_completion', [a:server_name, l:position, a:opt, a:ctx]),
         \ })
 endfunction
 
-function! s:handle_completion(server_name, opt, ctx, data) abort
+function! s:handle_completion(server_name, position, opt, ctx, data) abort
     if lsp#client#is_error(a:data) || !has_key(a:data, 'response') || !has_key(a:data['response'], 'result')
         return
     endif
 
-    " for register vim-lsp managed user data
-    let l:result = a:data['response']['result']
-    if type(l:result) == type([])
-        let l:items = copy(l:result)
-    elseif type(l:result) == type({})
-        let l:items = copy(l:result['items'])
-    else
-        let l:items = []
-    endif
+    let l:options = {
+        \ 'server': a:server_name,
+        \ 'position': a:position,
+        \ 'response': a:data['response'],
+        \ }
+    let g:deoplete#source#vim_lsp#_items = lsp#omni#get_vim_completion_items(l:options)['items']
 
-    " pass to deoplete reference variable and call completion
-    let g:deoplete#source#vim_lsp#_items = map(l:items, 'lsp#omni#get_vim_completion_item(v:val, a:server_name)')
     let g:deoplete#source#vim_lsp#_done = 1
     let l:ctx = a:ctx
     let g:deoplete#source#vim_lsp#_context = l:ctx
+
     if index(['i', 'ic', 'ix'], mode()) >= 0
         call deoplete#auto_complete()
     endif