PEGTL/tests/devel-usability/hello_world.cpp

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// Copyright (c) 2014-2019 Dr. Colin Hirsch and Daniel Frey
// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/
#include <iostream>
#include <string>
#include <tao/pegtl.hpp>
namespace pegtl = tao::pegtl;
namespace hello
{
// clang-format off
struct prefix : pegtl::string< 'H', 'e', 'l', 'l', 'o', ',', ' ' > {};
struct name : pegtl::plus< pegtl::alpha > {};
struct grammar : pegtl::must< prefix, name, pegtl::one< '!' >, pegtl::eof > {};
// clang-format on
template< typename Rule >
struct action : pegtl::nothing<Rule>
{};
template<>
struct action< name >
{
template< typename Input >
static void apply( const Input& in, std::string& v )
{
v = in.string();
}
};
} // namespace hello
int main( int argc, char** argv )
{
if( argc > 1 ) {
std::string name;
pegtl::argv_input<> in( argv, 1 );
pegtl::parse< hello::grammar, hello::action >( in, name );
std::cout << "Good bye, " << name << "!" << std::endl;
}
}