simpliest c++ example

src/lexer.l

@@ -1,28 +1,35 @@
-%option reentrant noyywrap nounput
+%option c++
+%option noyywrap
+%option yyclass="Scanner"
 
 %{
-#include <iostream>
 #include "../build/parser.hpp"
+#include <string>
 
-#define YY_DECL yy::Parser::symbol_type yylex(yyscan_t yyscanner, yy::location& loc)
-
-#define YY_USER_ACTION loc.columns(yyleng);
-#define yyterminate() return yy::Parser::make_END(loc)
+class Scanner : public yyFlexLexer {
+public:
+    Scanner(std::istream* in) : yyFlexLexer(in) {}
+    
+    int yylex(); 
 
+    int lex(yy::parser::semantic_type* yylval) {
+        this->yylval = yylval;
+        return yylex();
+    }
+    
+private:
+    yy::parser::semantic_type* yylval;
+};
 
+int scanner_lex(yy::parser::semantic_type* yylval) {
+    static Scanner scanner(&std::cin);
+    return scanner.lex(yylval);
+}
 %}
 
 %%
-
-%{
-	loc.step();
-%}
-
-
-function       	{return yy::Parser::make_FUNCTION(loc);}
-
-[ \n\r\t\v]		{}
-
-.				{std::cerr << loc << ": " << "token error" << std::endl; exit(1);}
-
-%%
+[0-9]+          { return yy::parser::token::TOK_NUMBER; }
+[a-zA-Z]+       { yylval->as<std::string>() = yytext; return yy::parser::token::TOK_WORD; }
+[ \t\r\n]+      { /* skip */ }
+.               { return yy::parser::token::TOK_CHAR; }
+%%