Check buftype is prompt

Improve incomplete handling

lua/cmp/utils/check.lua

@@ -0,0 +1,18 @@
+local check = {}
+
+check.ok = function()
+  local ng = false
+  ng = ng or vim.api.nvim_buf_get_option(0, 'buftype') == 'prompt'
+  ng = ng or string.sub(vim.api.nvim_get_mode().mode, 1, 1) ~= 'i'
+  return not ng
+end
+
+check.wrap = function(callback)
+  return function(...)
+    if check.ok() then
+      callback(...)
+    end
+  end
+end
+
+return check