Going "variant"

Author: mdhooge

mc_lexer.l

@@ -41,7 +41,10 @@ typedef MC::MC_Parser::token token;
             }
 
 [a-zA-Z]+   { 
-               yylval->sval = STOKEN( yytext );  
+               // Section 10.1.5.1 of the 3.0.2 Bison Manual says the following should work
+               // yylval.build( yytext );
+               // But it doesn't.
+               yylval->build<std::string>( yytext );
                return( token::WORD );      
             }
 

mc_parser.yy

@@ -10,6 +10,16 @@
       class MC_Driver;
       class MC_Scanner;
    }
+
+// The following definitions is missing when %locations isn't used
+# ifndef YY_NULLPTR
+#  if defined __cplusplus && 201103L <= __cplusplus
+#   define YY_NULLPTR nullptr
+#  else
+#   define YY_NULLPTR 0
+#  endif
+# endif
+
 }
 
 %parse-param { MC_Scanner  &scanner  }
@@ -27,21 +37,15 @@
 #define yylex scanner.yylex
 }
 
-/* token types */
-%union {
-   std::string *sval;
-}
-
-%token            END    0     "end of file"
-%token            UPPER
-%token            LOWER
-%token   <sval>   WORD
-%token            NEWLINE
-%token            CHAR
-
+%define api.value.type variant
+%define parse.assert
 
-/* destructor rule for <sval> objects */
-%destructor { if ($$)  { delete ($$); ($$) = nullptr; } } <sval>
+%token               END    0     "end of file"
+%token               UPPER
+%token               LOWER
+%token <std::string> WORD
+%token               NEWLINE
+%token               CHAR
 
 
 %%
@@ -56,7 +60,7 @@ list
 item
   : UPPER   { driver.add_upper(); }
   | LOWER   { driver.add_lower(); }
-  | WORD    { driver.add_word( *$1 ); }
+  | WORD    { driver.add_word( $1 ); }
   | NEWLINE { driver.add_newline(); }
   | CHAR    { driver.add_char(); }
   ;