FromString.h

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/*
 * Copyright (C) by
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 * and
 *   Neuroinformatics and Cognitive Robotics Labs (NICR) at TU Ilmenau, GERMANY
 * All rights reserved.
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 * Contact: info@mira-project.org
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 */

#ifndef _MIRA_FROMSTRING_H_
#define _MIRA_FROMSTRING_H_

#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/trim.hpp>

#include <error/Exceptions.h>

#include <math/Math.h>

#include <utils/FromToStringConstants.h>


namespace mira {


namespace Private {

template <typename T>
inline T genericFromString(const std::string& str)
{
    auto trimmed = boost::algorithm::trim_copy(str);

    try {
        return boost::lexical_cast<T>(trimmed);
    }
    catch (boost::bad_lexical_cast &e) {
        MIRA_THROW(XIO, "Failed to convert value from string '" << str << "': " << e.what());
    }
}

template <typename T>
inline T fpFromString(const std::string& str)
{
    try {
        return genericFromString<T>(str);
    } catch(XIO&) {
        if(str==MIRA_TOSTRING_NAN)
            return std::numeric_limits<T>::quiet_NaN();
        else if(str==MIRA_TOSTRING_POSITIVE_INF)
            return std::numeric_limits<T>::infinity();
        else if(str==MIRA_TOSTRING_NEGATIVE_INF)
            return -std::numeric_limits<T>::infinity();
        else
            throw; // we could not handle the exception, so rethrow it
    }
}

template <typename T>
inline T charFromString(const std::string& str)
{
    int val = genericFromString<int>(str);

    if(val>std::numeric_limits<T>::max())
        MIRA_THROW(XIO, "Overflow while converting value from string '" << 
                   str << "', max: " << (int)std::numeric_limits<T>::max());
    if(val<std::numeric_limits<T>::min())
        MIRA_THROW(XIO, "Underflow while converting value from string '" << 
                   str << "', min: " << (int)std::numeric_limits<T>::min());

    return static_cast<T>(val);
}

} // Private


template <typename T>
class FromHex
{
public:
    operator T() const { return value; }
    friend std::istream& operator>>(std::istream& iStream, FromHex<T>& oValue)
    {
        iStream >> std::hex >> oValue.value;
        return iStream;
    }

    T value;
};

template <typename T>
class FromOct
{
public:
    operator T() const { return value; }
    friend std::istream& operator>>(std::istream& iStream, FromOct<T>& oValue)
    {
        iStream >> std::oct >> oValue.value;
        return iStream;
    }

    T value;
};


template <typename T>
T fromString(const std::string& str)
{
    return Private::genericFromString<T>(str);
}

template <>
inline char fromString<char>(const std::string& str)
{
    return Private::charFromString<char>(str);
}

template <>
inline signed char fromString<signed char>(const std::string& str)
{
    return Private::charFromString<signed char>(str);
}

template <>
inline unsigned char fromString<unsigned char>(const std::string& str)
{
    return Private::charFromString<unsigned char>(str);
}

template <>
inline std::string fromString<std::string>(const std::string& str)
{
    return str;
}

template <>
inline float fromString<float>(const std::string& str)
{
    return Private::fpFromString<float>(str);
}

template <>
inline double fromString<double>(const std::string& str)
{
    return Private::fpFromString<double>(str);
}

template <>
inline long double fromString<long double>(const std::string& str)
{
    return Private::fpFromString<long double>(str);
}

template <>
inline bool fromString<bool>(const std::string & str)
{
    auto trimmed = boost::algorithm::trim_copy(str);

    // case-insensitive compare
    if (boost::iequals(trimmed, "true"))
        return true;

    if (!boost::iequals(trimmed, "false"))
        MIRA_THROW(XIO, "Failed to convert bool value from string '" << str << "'");

    return false;
}


} // namespace

#endif