gpr-tools/source/app/common/argument_parser/program_options_lite.h

/* The copyright in this software is being made available under the BSD
 * License, included below. This software may be subject to other third party
 * and contributor rights, including patent rights, and no such rights are
 * granted under this license.
 *
 * Copyright (c) 2010-2015, ITU/ISO/IEC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <iostream>
#include <sstream>
#include <string>
#include <list>
#include <map>

#ifndef __PROGRAM_OPTIONS_LITE__
#define __PROGRAM_OPTIONS_LITE__

namespace program_options_lite
{
    struct Options;
    
    struct ParseFailure : public std::exception
    {
        ParseFailure(std::string arg0, std::string val0) throw()
        : arg(arg0), val(val0)
        {}
        
        ~ParseFailure() throw() {};
        
        std::string arg;
        std::string val;
        
        const char* what() const throw() { return "Option Parse Failure"; }
    };
    
    void doHelp(std::ostream& out, Options& opts, unsigned columns = 80);
    unsigned parseGNU(Options& opts, unsigned argc, const char* argv[]);
    unsigned parseSHORT(Options& opts, unsigned argc, const char* argv[]);
    std::list<const char*> scanArgv(Options& opts, unsigned argc, const char* argv[]);
    void scanLine(Options& opts, std::string& line);
    void scanFile(Options& opts, std::istream& in);
    void setDefaults(Options& opts);
    void parseConfigFile(Options& opts, const std::string& filename);
    bool storePair(Options& opts, const std::string& name, const std::string& value);
    
    /** OptionBase: Virtual base class for storing information relating to a
     * specific option This base class describes common elements.  Type specific
     * information should be stored in a derived class. */
    struct OptionBase
    {
        OptionBase(const std::string& name, const std::string& desc)
        : opt_string(name), opt_desc(desc)
        {};
        
        virtual ~OptionBase() {}
        
        /* parse argument arg, to obtain a value for the option */
        virtual void parse(const std::string& arg) = 0;
        /* set the argument to the default value */
        virtual void setDefault() = 0;
        
        std::string opt_string;
        std::string opt_desc;
    };
    
    /** Type specific option storage */
    template<typename T>
    struct Option : public OptionBase
    {
        Option(const std::string& name, T& storage, T default_val, const std::string& desc)
        : OptionBase(name, desc), opt_storage(storage), opt_default_val(default_val)
        {}
        
        void parse(const std::string& arg);
        
        void setDefault()
        {
            opt_storage = opt_default_val;
        }
        
        T& opt_storage;
        T opt_default_val;
    };
    
    /* Generic parsing */
    template<typename T>
    inline void
    Option<T>::parse(const std::string& arg)
    {
        std::istringstream arg_ss (arg,std::istringstream::in);
        arg_ss.exceptions(std::ios::failbit);
        try
        {
            arg_ss >> opt_storage;
        }
        catch (...)
        {
            throw ParseFailure(opt_string, arg);
        }
    }
    
    /* string parsing is specialized -- copy the whole string, not just the
     * first word */
    template<>
    inline void
    Option<std::string>::parse(const std::string& arg)
    {
        opt_storage = arg;
    }
    
    /** Option class for argument handling using a user provided function */
    struct OptionFunc : public OptionBase
    {
        typedef void (Func)(Options&, const std::string&);
        
        OptionFunc(const std::string& name, Options& parent_, Func *func_, const std::string& desc)
        : OptionBase(name, desc), parent(parent_), func(func_)
        {}
        
        void parse(const std::string& arg)
        {
            func(parent, arg);
        }
        
        void setDefault()
        {
            return;
        }
        
    private:
        Options& parent;
        void (*func)(Options&, const std::string&);
    };
    
    class OptionSpecific;
    struct Options
    {
        ~Options();
        
        OptionSpecific addOptions();
        
        struct Names
        {
            Names() : opt(0) {};
            ~Names()
            {
                if (opt)
                {
                    delete opt;
                }
            }
            std::list<std::string> opt_long;
            std::list<std::string> opt_short;
            OptionBase* opt;
        };
        
        void addOption(OptionBase *opt);
        
        typedef std::list<Names*> NamesPtrList;
        NamesPtrList opt_list;
        
        typedef std::map<std::string, NamesPtrList> NamesMap;
        NamesMap opt_long_map;
        NamesMap opt_short_map;
    };
    
    /* Class with templated overloaded operator(), for use by Options::addOptions() */
    class OptionSpecific
    {
    public:
        OptionSpecific(Options& parent_) : parent(parent_) {}
        
        /**
         * Add option described by name to the parent Options list,
         *   with storage for the option's value
         *   with default_val as the default value
         *   with desc as an optional help description
         */
        template<typename T>
        OptionSpecific&
        operator()(const std::string& name, T& storage, T default_val, const std::string& desc = "")
        {
            parent.addOption(new Option<T>(name, storage, default_val, desc));
            return *this;
        }
        
        /**
         * Add option described by name to the parent Options list,
         *   with desc as an optional help description
         * instead of storing the value somewhere, a function of type
         * OptionFunc::Func is called.  It is upto this function to correctly
         * handle evaluating the option's value.
         */
        OptionSpecific&
        operator()(const std::string& name, OptionFunc::Func *func, const std::string& desc = "")
        {
            parent.addOption(new OptionFunc(name, parent, func, desc));
            return *this;
        }
    private:
        Options& parent;
    };
    
} /* namespace: program_options_lite */


#endif // __PROGRAM_OPTIONS_LITE__