Fix order of operations for prefix and '*', '/'

The problem is that Prefix did not properly participate in
operator precedence. I've fixed this, at least for the moment,
by adding a final depth of precedence that can be called when
the depth gets to the bottom.

closes #285

include/chaiscript/language/chaiscript_parser.hpp

@@ -219,6 +219,10 @@ namespace chaiscript
         m_operators.emplace_back(AST_Node_Type::Multiplication);
         m_operator_matches.emplace_back(std::initializer_list<std::string>({"*", "/", "%"}));
 
+        // Prefix placeholder
+        m_operators.emplace_back(AST_Node_Type::Prefix);
+        m_operator_matches.emplace_back(std::initializer_list<std::string>({}));
+
         for (auto & elem : m_alphabet) {
           std::fill(std::begin(elem), std::end(elem), false);
         }
@@ -2197,7 +2201,7 @@ namespace chaiscript
         bool retval = false;
         const auto prev_stack_top = m_match_stack.size();
 
-        if (t_precedence < m_operators.size()) {
+        if (m_operators[t_precedence] != AST_Node_Type::Prefix) {
           if (Operator(t_precedence+1)) {
             retval = true;
             if (Operator_Helper(t_precedence)) {
@@ -2257,8 +2261,7 @@ namespace chaiscript
               } while (Operator_Helper(t_precedence));
             }
           }
-        }
-        else {
+        } else {
           return Value();
         }
 

unittests/precedence_4.chai

@@ -0,0 +1,4 @@
+
+var i = 2;
+
+assert_equal(++i * i, 9)