Unit.h

#pragma once
 
#include <QExplicitlySharedDataPointer>
 
#include "Forward.h"
 
namespace knowCore
{
  class UnitRegistration;
  class Unit
  {
    friend class UnitRegistration;
  public:
    enum class Prefix
    {
      Yotta,
      Zetta,
      Exa,
      Peta,
      Tera,
      Giga,
      Mega,
      Kilo,
      Hecto,
      Deca,
      Base,
      Deci,
      Centi,
      Milli,
      Micro,
      Nano,
      Pico,
      Femto,
      Atto,
      Zepto,
      Yocto
    };
  public:
    static Unit empty();
    Unit();
    Unit(const Unit& _unit);
    Unit& operator=(const Unit& _unit);
    ~Unit();
    QString symbol() const;
    QString name() const;
    knowCore::Uri uri() const;
    Unit base() const;
    QList<Unit> derivedUnits() const;
    bool operator==(const Unit& _unit) const;
    bool isValid() const;
    cres_qresult<Unit> operator/(const Unit& _unit) const;
    cres_qresult<Unit> operator*(const Unit& _unit) const;
    qreal scale() const;
  public:
    static QString prefixSymbol(Prefix p);
    static QString prefixName(Prefix p);
    static qreal prefixScale(Prefix p);
  public:
    static QList<Unit> baseUnits();
    static cres_qresult<Unit> bySymbol(const QString& _symbol);
    static cres_qresult<Unit> byName(const QString& _name);
    static cres_qresult<Unit> byUri(const knowCore::Uri& _symbol);
  private:
    struct Private;
    QExplicitlySharedDataPointer<const Private> d;
    Unit(const QExplicitlySharedDataPointer<const Private>& _d);
  };
  class UnitRegistration
  {
  public:
    using PrefixToScale = std::function<double(Unit::Prefix)>;
    using PrefixesToScale = std::function<double(const QList<Unit::Prefix>&)>;
    using PrefixToString = std::function<QString(Unit::Prefix)>;
  public:
    UnitRegistration(const QString& _symbol, const QString& _name, const QString& _uri,
                     const QList<Unit::Prefix>& _prefixes, const PrefixToScale& _scale,
                     const PrefixToString& _to_uri);
    UnitRegistration(const QString& _symbol, const QString& _name, const QString& _uri,
                     const QList<QList<Unit::Prefix>>& _prefixes, const PrefixesToScale& _scale,
                     const PrefixToString& _to_uri);
    ~UnitRegistration();
  };
 
} // namespace knowCore
 
#define __KNOWCORE_UNIT_ADD_PREFIX(X, I) knowCore::Unit::Prefix::X,
 
#define KNOWCORE_UNIT_PREFIX_LIST(...) KNOWCORE_FOREACH(__KNOWCORE_UNIT_ADD_PREFIX, __VA_ARGS__)
 
#define KNOWCORE_DEFINE_UNIT(_CPP_SYMBOL_, _SYMBOL_, _NAME_, _URI_, _SCALE_F_, _TO_URI_F_, ...)    \
  knowCore::UnitRegistration __KNOWCORE_UNIQUE_STATIC_NAME(_CPP_SYMBOL_)(                          \
    _SYMBOL_, _NAME_, _URI_, {KNOWCORE_UNIT_PREFIX_LIST(__VA_ARGS__)}, _SCALE_F_, _TO_URI_F_)
 
#define KNOWCORE_DEFINE_COMPOSITE_UNIT(_CPP_SYMBOL_, _SYMBOL_, _NAME_, _URI_, _SCALE_F_,           \
                                       _TO_URI_F_, ...)                                            \
  knowCore::UnitRegistration __KNOWCORE_UNIQUE_STATIC_NAME(_CPP_SYMBOL_)(                          \
    _SYMBOL_, _NAME_, _URI_, {__VA_ARGS__}, _SCALE_F_, _TO_URI_F_)
 
#include "Formatter.h"
 
clog_format_declare_formatter(knowCore::Unit)
{
  return std::format_to(ctx.out(), "{}", p.symbol());
}