options_description.cpp

C++的一个好库。。。现在很流行

// Copyright Vladimir Prus 2002-2004.
// Copyright Bertolt Mildner 2004.
// 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)


#define BOOST_PROGRAM_OPTIONS_SOURCE
#include <boost/program_options/config.hpp>
#include <boost/program_options/options_description.hpp>
// FIXME: this is only to get multiple_occureces class
// should move that to a separate headers.
#include <boost/program_options/parsers.hpp>


#include <boost/lexical_cast.hpp>
#include <boost/tokenizer.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/throw_exception.hpp>

#include <cassert>
#include <climits>
#include <cstring>
#include <cstdarg>
#include <sstream>
using namespace std;

namespace boost { namespace program_options {

    option_description::option_description()
    {
    }
    
    option_description::
    option_description(const char* name,
                       const value_semantic* s)
    : m_value_semantic(s)
    {
        this->set_name(name);
    }
                                           

    option_description::
    option_description(const char* name,
                       const value_semantic* s,
                       const char* description)
    : m_description(description), m_value_semantic(s)
    {
        this->set_name(name);
    }

    option_description::~option_description()
    {
    }

    bool 
    option_description::match(const std::string& option, bool approx) const
    {
        bool result = false;
        if (!m_long_name.empty()) {

            if (*m_long_name.rbegin() == '*')
            {
                // The name ends with '*'. Any specified name with the given
                // prefix is OK.
                if (option.find(m_long_name.substr(0, m_long_name.length()-1))
                    == 0)
                    result = true;
            }

            if (approx)
            {
                if (m_long_name.find(option) == 0)
                    result = true;
            }
            else
            {
                if (m_long_name == option)
                    result = true;
            }
        }
         
        if (m_short_name == option)
            result = true;

        return result;        
    }

    const std::string& 
    option_description::key(const std::string& option) const
    {        
        if (!m_long_name.empty()) 
            if (m_long_name.find('*') != string::npos)
                // The '*' character means we're long_name
                // matches only part of the input. So, returning
                // long name will remove some of the information,
                // and we have to return the option as specified
                // in the source.
                return option;
            else
                return m_long_name;
        else
            return m_short_name;
    }

    const std::string&
    option_description::long_name() const
    {
        return m_long_name;
    }

    option_description&
    option_description::set_name(const char* _name)
    {
        std::string name(_name);
        string::size_type n = name.find(',');
        if (n != string::npos) {
            assert(n == name.size()-2);
            m_long_name = name.substr(0, n);
            m_short_name = '-' + name.substr(n+1,1);
        } else {
            m_long_name = name;
        }
        return *this;
    }

    const std::string&
    option_description::description() const
    {
        return m_description;
    }

    shared_ptr<const value_semantic>
    option_description::semantic() const
    {
        return m_value_semantic;
    }
    
    std::string 
    option_description::format_name() const
    {
        if (!m_short_name.empty())
            return string(m_short_name).append(" [ --").
            append(m_long_name).append(" ]");
        else
            return string("--").append(m_long_name);
    }

    std::string 
    option_description::format_parameter() const
    {
        if (m_value_semantic->max_tokens() != 0)
            return m_value_semantic->name();
        else
            return "";
    }

    options_description_easy_init::
    options_description_easy_init(options_description* owner)
    : owner(owner)
    {}

    options_description_easy_init&
    options_description_easy_init::
    operator()(const char* name,
               const char* description)
    {
        // Create untypes semantic which accepts zero tokens: i.e. 
        // no value can be specified on command line.
        // FIXME: does not look exception-safe
        shared_ptr<option_description> d(
            new option_description(name, new untyped_value(true), description));

        owner->add(d);
        return *this;
    }

    options_description_easy_init&
    options_description_easy_init::
    operator()(const char* name,
               const value_semantic* s)
    {
        shared_ptr<option_description> d(new option_description(name, s));
        owner->add(d);
        return *this;
    }

    options_description_easy_init&
    options_description_easy_init::
    operator()(const char* name,
               const value_semantic* s,
               const char* description)
    {
        shared_ptr<option_description> d(new option_description(name, s, description));

        owner->add(d);
        return *this;
    }

    options_description::options_description(unsigned line_length)
    : m_line_length(line_length)
    {}

    options_description::options_description(const string& caption,
                                             unsigned line_length)
    : m_caption(caption), m_line_length(line_length)
    {}

    void
    options_description::add(shared_ptr<option_description> desc)
    {
        m_options.push_back(desc);
        belong_to_group.push_back(false);
    }

    options_description&
    options_description::add(const options_description& desc)
    {
        shared_ptr<options_description> d(new options_description(desc));
        groups.push_back(d);

        for (size_t i = 0; i < desc.m_options.size(); ++i) {
            add(desc.m_options[i]);
            belong_to_group.back() = true;
        }

        return *this;
    }

    options_description_easy_init
    options_description::add_options()
    {       
        return options_description_easy_init(this);
    }

    const option_description&
    options_description::find(const std::string& name, bool approx) const
    {
        const option_description* d = find_nothrow(name, approx);
        if (!d)
            boost::throw_exception(unknown_option(name));
        return *d;
    }

    const std::vector< shared_ptr<option_description> >& 
    options_description::options() const
    {
        return m_options;
    }

    const option_description* 
    options_description::find_nothrow(const std::string& name, 
                                      bool approx) const
    {
        int found = -1;
        // We use linear search because matching specified option
        // name with the declared option name need to take care about
        // case sensitivity and trailing '*' and so we can't use simple map.
        for(unsigned i = 0; i < m_options.size(); ++i)
        {
            if (m_options[i]->match(name, approx))
            {
                if (found != -1)
                {
                    vector<string> alts;
                    // FIXME: the use of 'key' here might not
                    // be the best approach.