xo-reader: refactor: streamline define_xs

include/xo/reader/define_xs.hpp

@@ -74,11 +74,6 @@ namespace xo {
 
             defexprstatetype defxs_type() const { return defxs_type_; }
 
-            bool admits_rightparen() const;
-            //bool admits_semicolon() const;
-            //bool admits_symbol() const;
-
-            // virtual void on_f64(..) override
             virtual void on_expr(ref::brw<Expression> expr,
                                  exprstatestack * p_stack,
                                  rp<Expression> * p_emit_expr) override;

src/reader/define_xs.cpp

@@ -25,29 +25,6 @@ namespace xo {
               def_expr_{std::move(def_expr)}
         {}
 
-        bool
-        define_xs::admits_rightparen() const {
-            switch (defxs_type_) {
-
-            case defexprstatetype::def_0:
-            case defexprstatetype::def_1:
-            case defexprstatetype::def_2:
-            case defexprstatetype::def_3:
-            case defexprstatetype::def_4:
-            case defexprstatetype::def_5:
-            case defexprstatetype::def_6:
-                return false;
-
-            case defexprstatetype::invalid:
-            case defexprstatetype::n_defexprstatetype:
-                /* unreachable */
-                assert(false);
-                return false;
-            }
-
-            return false;
-        }
-
         void
         define_xs::on_expr(ref::brw<Expression> expr,
                            exprstatestack * /* p_stack */,
@@ -271,12 +248,7 @@ namespace xo {
 
             constexpr const char * self_name = "exprstate::on_rightparen";
 
-            if (!this->admits_rightparen())
+            this->illegal_input_error(self_name, tk);
-            {
-                this->illegal_input_error(self_name, tk);
-            }
-
-            assert(false); /* inserting this during refactor..? */
         }
 
         void