TypeUtils.h

/*
 
MIT License
 
Copyright (c) 2017 FMI Open Development / Markus Peura, first.last@fmi.fi
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 
*/
/*
Part of Rack development has been done in the BALTRAD projects part-financed
by the European Union (European Regional Development Fund and European
Neighbourhood Partnership Instrument, Baltic Sea Region Programme 2007-2013)
*/
 
#ifndef DRAIN_TYPE_UTILS
#define DRAIN_TYPE_UTILS
 
#include <cmath>
#include <limits>
#include <set>
#include <typeinfo>
 
 
#include "Type.h"
#include "RegExp.h"
 
namespace drain {
 
 
template <class S>
struct typeLimits {
 
    static inline
    long int getMinI(){
        return static_cast<long int>(std::numeric_limits<S>::min());
    }
 
    static inline
    unsigned long int getMaxI(){
        return static_cast<unsigned long int>(std::numeric_limits<S>::max());
    }
 
    static inline
    double getMaxF(){
        return static_cast<double>(std::numeric_limits<S>::max());
    }
 
};
 
 
template <> inline long int typeLimits<void>::getMinI(){ return 0l; }
template <> inline unsigned long int typeLimits<void>::getMaxI(){ return 0l; }
template <> inline   double typeLimits<void>::getMaxF(){ return 0.0; }
 
template <> inline long int typeLimits<std::string>::getMinI(){ return 0l; }
template <> inline unsigned long int typeLimits<std::string>::getMaxI(){ return 0l; }
template <> inline   double typeLimits<std::string>::getMaxF(){ return 0.0; }
 
 
// THIS WORKS WELL!
template <class D>
class typeLimiter  {
 
public:
 
    typedef D (*value_t)(D);
 
    template <class S, class T>
    static inline
    T callback(){
        if (std::numeric_limits<S>::is_integer)
            return &typeLimiter<D>::limitInteger<S,D>;
        else
            return &typeLimiter<D>::limitFloat<S,D>;
    }
 
 
protected:
 
 
    template <class S, class T>
    static
    T limitInteger(T x){
 
        static const T minValue = static_cast<T>(typeLimits<S>::getMinI());
        static const T maxValue = static_cast<T>(typeLimits<S>::getMaxI());
        if (x < minValue)
            return minValue;
        else if (x > maxValue)
            return maxValue;
 
        return x;
    }
 
 
    template <class S, class T>
    static
    T limitFloat(T x){
 
        static const T maxValue = static_cast<T>(typeLimits<S>::getMaxF());
        // notice minus sign
        if (x < -maxValue)
            return -maxValue;
        else if (x > maxValue)
            return maxValue;
 
        return x;
    }
 
 
 
};
 
struct TypeUtils {
 
 
 
    static
    const std::type_info & guessType(const std::string & value);
 
 
    static
    const std::type_info & guessType(double d, const std::type_info & type = typeid(unsigned char));
 
 
 
 
    template <class C>
    static
    const std::type_info & guessArrayType(const C & container);
 
 
    template <typename T, typename S>
    static inline
    bool isWithinRange(const S & x){
        // Call limit(), eg. check if 352 stays within [0,256[
        return (Type::call<typeLimiter<S> >(typeid(T))(x) == x);
    }
 
    template <typename S>
    static inline
    bool isWithinRange(const S & x, const std::type_info & type){
        // Call limit(), eg. check if 352 stays within uchar range [0,256[
        return (Type::call<typeLimiter<S> >(type)(x) == x);
    }
 
    //   *   \tparam S - source type, typically with a large value range, double for example
 
 
    template <typename T=unsigned char>
    static inline
    const std::type_info & minimizeIntType(double value){
        // a bit clumsy, as calls Type::call().
        return minimizeIntType(value, typeid(T));
    }
 
 
    static
    const std::type_info & minimizeIntType(double value, const std::type_info & type = typeid(unsigned char));
 
 
    static
    const drain::RegExp  trueRegExp; // ignore case
 
    static
    const drain::RegExp falseRegExp; // ignore case
 
    // TODO: better whitespace
    static
    const drain::RegExp numeralRegExp;
 
};
 
 
 
/*
template <typename T=unsigned char>
const std::type_info & TypeUtils::minimizeIntType(double d){ // , const std::type_info & type = typeid(unsigned char)){
 
    // const bool IS_INTEGER = (d == ::trunc(d));
 
    if (d != ::trunc(d)){
        return typeid(double); // later, also float option?
    }
 
 
    if (isWithinRange<T>(d)){
        return typeid(T);
    }
 
    static const std::type_info & type = typeid(T);
 
    // Type::call<isSigned>(type)
    // Later, directly "inline" through type specification ?
    if (std::numeric_limits<T>::is_signed){
        // throw std::runtime_error(StringBuilder<' '>(__FUNCTION__, "  requested signed type: ", TypeName<T>::str()));
        if (&type == &typeid(signed char)){
            return minimizeIntType<signed short>(d);
        }
        else if (&type == &typeid(signed short)){
            return minimizeIntType<signed int>(d);
        }
        else if (&type == &typeid(signed int)){
            return minimizeIntType<signed long>(d);
        }
    }
    else {
        if (&type == &typeid(unsigned char)){
            return minimizeIntType<unsigned short>(d);
        }
        else if (&type == &typeid(unsigned short)){
            return minimizeIntType<unsigned int>(d);
        }
        else if (&type == &typeid(unsigned int)){
            return minimizeIntType<unsigned long>(d);
        }
    }
 
    return typeid(double);
 
}
*/
 
 
 
/*
 *   \tparam C - contrainer, esp. std::list or std::vector
 */
template <class C>
const std::type_info & TypeUtils::guessArrayType(const C & l){
 
 
    typedef std::set<const std::type_info *> typeset;
 
    typeset s;
    for (typename C::const_iterator it = l.begin(); it != l.end(); ++it) {
        s.insert(& guessType(*it));
    }
 
    if (s.find(& typeid(std::string)) != s.end())
        return typeid(std::string);
 
    if (s.find(& typeid(double)) != s.end())
        return typeid(double);
 
    if (s.find(& typeid(int)) != s.end())
        return typeid(int);
 
    if (s.find(& typeid(bool)) != s.end())
        return typeid(bool);
 
    // General fallback solution
    return typeid(std::string);
 
}
 
 
 
class typesetter {
public:
 
    template <class S, class T>
    static
    void callback(T & target){
        target.template setType<S>();
    }
};
 
 
 
class sizeGetter {
 
public:
 
    typedef std::size_t value_t;
 
    template <class S, class T>
    static inline
    T callback(){
        return static_cast<T>(getSize<S>()); // static cast unneeded in these ?
    }
 
protected:
 
    // Must be here to get template<void> implemented
    template <class S>
    static inline
    size_t getSize(){
        return sizeof(S);
    }
 
};
 
template <>
inline
size_t sizeGetter::getSize<void>(){
    return 0;
}
// todo:: std::string?
 
 
 
 
 
 
 
 
class compactName {
 
public:
 
    typedef const std::string & value_t;
 
    template <class S, class T>
    static
    T callback(){
 
        static std::string s;
 
        if (s.empty()){
            std::stringstream sstr;
            size_t n = sizeGetter::callback<S, std::size_t>();
            if (std::numeric_limits<S>::is_specialized){
                if (std::numeric_limits<S>::is_integer){
                    if (!std::numeric_limits<S>::is_signed)
                        sstr << 'u';
                    // sstr << ' ';
                    if (n==1)
                        sstr << "char";
                    else
                        sstr << "int";
                }
                else
                    sstr << "float";
            }
            else {
                if (typeid(S) == typeid(bool))
                    sstr << "bool";
                else if (n==0)
                    sstr << "void";
                else
                    sstr << "other"; // pointer, for example?
            }
            //sstr << (8 * n);
            s = sstr.str();
        }
 
        return s;
 
    }
 
};
 
class complexName {
 
public:
 
    //typedef std::string value_t;
    typedef const std::string & value_t;
 
    template <class S, class T>
    static
    T callback(){
        // typedef std::numeric_limits<S> nlim;
        // return numInfo<nlim::is_specialized, nlim::is_integer, nlim::is_signed>::s;
        static std::string s;
 
        if (s.empty()){
            std::stringstream sstr;
            size_t n = sizeGetter::callback<S, std::size_t>();
            if (std::numeric_limits<S>::is_specialized){
                if (std::numeric_limits<S>::is_integer){
                    if (std::numeric_limits<S>::is_signed)
                        sstr << "signed";
                    else
                        sstr << "unsigned";
                    sstr << ' ';
                    if (n==1)
                        sstr << "char";
                    else
                        sstr << "integer";
                }
                else
                    sstr << "float";
            }
            else {
                if (typeid(S) == typeid(bool))
                    sstr << "bool";
                else if (n==0)
                    sstr << "void"; // "uninitialized";
                else
                    sstr << "non-numeric";
            }
            sstr << " (" << (8 * n) << "b)";
            s = sstr.str();
        }
 
        return s;
 
    }
 
 
 
};
 
 
 
 
class nameGetter {
 
public:
 
    typedef const char * value_t;
 
    template <class S, class T>
    static inline
    T callback(){
        return typeid(S).name();
    }
 
};
 
/*
 *  Usage:
 *
 *  Type::call<drain::typeIsFundamental>(t)
 *
 */
class typeIsFundamental {
 
public:
 
    typedef bool value_t;
 
    template <class S, class T>
    static inline
    T callback(){ return std::is_fundamental<S>::value; }
 
};
 
class isSigned {  // F2
 
public:
 
    typedef bool value_t;
 
    template <class S, class T>
    static inline
    T callback(){
        return static_cast<T>( std::numeric_limits<S>::is_signed);
    }
 
};
 
 
 
class typeIsScalar {
 
public:
 
    typedef bool value_t;
 
    template <class S, class T>
    static inline
    T callback(){ return std::numeric_limits<S>::is_specialized; }
 
};
 
class typeIsInteger { // F2
 
public:
 
    typedef bool value_t;
 
    template <class S, class T>
    static inline
    T callback(){ return std::numeric_limits<S>::is_integer; }
 
};
 
class typeIsFloat { // F2
 
public:
 
    typedef bool value_t;
 
    template <class S, class T>
    static inline
    T callback(){
        return (typeid(S)==typeid(float)) || (typeid(S)==typeid(double));
        //return std::numeric_limits<S>::is_float;
    }
    // { return (typeid(S)==typeid(float)) || (typeid(S)==typeid(double)); }
 
};
 
 
 
class typeIsSmallInt {
 
public:
 
    typedef bool value_t;
 
    template <class S, class D>
    static inline
    D callback(){
        return (typeid(S) == typeid(char)) || (typeid(S) == typeid(unsigned char)) || (typeid(S) == typeid(short)) || (typeid(S) == typeid(unsigned short));
    }
};
 
 
 
 
 
class typeMin {
 
public:
 
    //typedef T value_t;
 
    template <class S, class D>
    static inline
    D callback(){
        if (std::numeric_limits<S>::is_integer)
            return static_cast<D>(+typeLimits<S>::getMinI());
        else
            return static_cast<D>(-typeLimits<S>::getMaxF());
    }
};
 
 
 
class typeMax {
 
public:
 
    //typedef T value_t;
 
    template <class S, class D>
    static inline
    D callback(){
        if (std::numeric_limits<S>::is_integer)
            return static_cast<D>(+typeLimits<S>::getMaxI());
        else
            return static_cast<D>(+typeLimits<S>::getMaxF());
    }
};
 
 
class typeNaturalMax {
 
public:
 
    typedef double value_t;
 
    template <class S, class D>
    static inline
    D callback(){
        if (typeIsSmallInt::callback<S,bool>())
            return static_cast<D>(typeLimits<S>::getMaxI());
        else
            return static_cast<D>(1.0);
    }
};
 
 
 
// Experimental template exercise... (works ok)
} // drain::
 
#endif /* TypeUTILS_H_ */