usql updates, lexer changes

usql/settings.cpp

@@ -12,16 +12,20 @@ std::vector<std::pair<std::string, std::string>> Settings::m_settings =
 	      std::make_pair("DOUBLE_FORMAT", "%.2f") };
 
 
-long Settings::string_to_date(const std::string &datestr) {
-	return ::string_to_date(datestr, get_setting("DATE_FORMAT"));
+
+long Settings::string_to_int(const std::string &intstr) {
+	return std::stoi(intstr); 
+}
+
+std::string Settings::int_to_string(long intval) {
+	return std::to_string(intval);
 }
 
 
-std::string Settings::date_to_string(long date) {
-	return ::date_to_string(date, get_setting("DATE_FORMAT"));
+double Settings::string_to_double(const std::string &doublestr) {
+	return std::stod(doublestr);	// TODO use fast parsing 
 }
-
-
+ 
 std::string Settings::double_to_string(double d) {
 	char buffer[32];
 	int r, buf_size = 32;
@@ -29,9 +33,37 @@ std::string Settings::double_to_string(double d) {
 	r = snprintf(buffer, buf_size, get_setting("DOUBLE_FORMAT").c_str(), d);
 	if (r > 0 && r < buf_size) return std::string(buffer);
 
+	// ?? return std::to_string(d);
 	return "ERROR";
 }
 
+
+long Settings::string_to_date(const std::string &datestr) {
+	return ::string_to_date(datestr, get_setting("DATE_FORMAT"));
+}
+
+std::string Settings::date_to_string(long date) {
+	return ::date_to_string(date, get_setting("DATE_FORMAT"));
+}
+
+
+bool Settings::string_to_bool(const std::string &boolstr) {
+	if (boolstr=="true" || boolstr == get_setting("BOOL_TRUE_LITERAL"))
+		return true;
+
+	if (boolstr=="false" || boolstr == get_setting("BOOL_FALSE_LITERAL"))
+		return false;
+
+	throw Exception("string_to_bool, unrecognized value: " + boolstr);
+}
+
+std::string Settings::bool_to_string(bool boolval) {
+	return boolval ? "true" : "false"; 
+}
+
+
+
+
 std::string Settings::get_setting(const std::string &name) {
 	for(const auto& pair : m_settings) {
 		if (pair.first == name) return pair.second;