add a completers option for specifying which completer to use for BufferCompleter

src/input_handler.cc

@@ -664,9 +664,11 @@ private:
     {
         if (not m_completions.is_valid())
         {
+            auto& completers = options()["completers"].get<std::vector<String>>();
             BufferIterator cursor = m_context.editor().main_selection().last();
+            if (contains(completers, "option"))
                 m_completions = complete_opt(cursor, m_context.options());
-            if (not m_completions.is_valid())
+            if (not m_completions.is_valid() and contains(completers, "word"))
                 m_completions = complete_word(cursor);
             if (not m_completions.is_valid())
                 return false;

src/option_manager.cc

@@ -119,6 +119,7 @@ GlobalOptions::GlobalOptions()
     declare_option<String>("filetype", "");
     declare_option<std::vector<String>>("completions", {});
     declare_option<std::vector<String>>("path", { "./", "/usr/include" });
+    declare_option<std::vector<String>>("completers", {"option", "word"});
     declare_option<bool>("insert_hide_sel", false);
 }
 

src/option_manager.hh

@@ -193,6 +193,8 @@ class OptionManagerWatcher_AutoRegister
 public:
     OptionManagerWatcher_AutoRegister(OptionManager& options)
         : AutoRegister(options) {}
+
+    OptionManager& options() { return registry(); }
 };