boost_1_45_0/libs/spirit/example/scheme/example/sexpr/sexpr_input_test.cpp

/*=============================================================================
    Copyright (c) 2001-2010 Joel de Guzman

    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#include <boost/config/warning_disable.hpp>

#include <input/sexpr.hpp>
#include <input/parse_sexpr_impl.hpp>
#include <utree/io.hpp>
#include <iostream>
#include <fstream>

inline std::ostream& println(std::ostream& out, scheme::utree const& val)
{
    out << val << std::endl;
    return out;
}

///////////////////////////////////////////////////////////////////////////////
//  Main program
///////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv)
{
    char const* filename = NULL;
    if (argc > 1)
    {
        filename = argv[1];
    }
    else
    {
        std::cerr << "Error: No input file provided." << std::endl;
        return 1;
    }

    std::ifstream in(filename, std::ios_base::in);

    if (!in)
    {
        std::cerr << "Error: Could not open input file: "
            << filename << std::endl;
        return 1;
    }

    // Ignore the BOM marking the beginning of a UTF-8 file in Windows
    char c = in.peek();
    if (c == '\xef')
    {
        char s[3];
        in >> s[0] >> s[1] >> s[2];
        s[3] = '\0';
        if (s != std::string("\xef\xbb\xbf"))
        {
            std::cerr << "Error: Unexpected characters from input file: "
                << filename << std::endl;
            return 1;
        }
    }

    scheme::utree result;
    if (scheme::input::parse_sexpr(in, result))
    {
        std::cout << "success: ";
        println(std::cout, result);
        std::cout << std::endl;
    }
    else
    {
        std::cout << "parse error" << std::endl;
    }

    return 0;
}