Added example/choice.cc

Author: yhirose

example/choice.cc

@@ -0,0 +1,28 @@
+//
+//  choice.cc
+//
+//  Copyright (c) 2023 Yuji Hirose. All rights reserved.
+//  MIT License
+//
+
+#include <cstdlib>
+#include <iostream>
+#include <peglib.h>
+
+using namespace peg;
+
+int main(void) {
+  parser parser(R"(
+type <- 'string' / 'int' / 'double'
+%whitespace <- [ \t\r\n]*
+  )");
+
+  parser["type"] = [](const SemanticValues &vs) {
+    std::cout << vs.choice() << std::endl;
+  };
+
+  if (parser.parse("int")) { return 0; }
+
+  std::cout << "syntax error..." << std::endl;
+  return -1;
+}