Action ADDCHARTOWORD is no longer appliable if the only input left are separators

transition_machine/src/ActionBank.cpp

@@ -640,7 +640,7 @@ std::vector<Action::BasicAction> ActionBank::str2sequence(const std::string & na
     auto undo = [](Config & c, Action::BasicAction &)
       {removeCharFromBuffer(c, "FORM", 0);};
     auto appliable = [](Config & c, Action::BasicAction &)
-      {return c.getTape("FORM").getHyp(0).size() <= 2000 && c.rawInput[c.rawInputHeadIndex] != '\t';};
+      {return c.getTape("FORM").getHyp(0).size() <= 2000 && c.rawInput[c.rawInputHeadIndex] != '\t' && !c.rawInputOnlySeparatorsLeft();};
     Action::BasicAction basicAction =
       {Action::BasicAction::Type::Write, "", apply, undo, appliable};