python/subclass.h

//  (C) Copyright David Abrahams 2000. Permission to copy, use, modify, sell and
//  distribute this software is granted provided this copyright notice appears
//  in all copies. This software is provided "as is" without express or implied
//  warranty, and with no claim as to its suitability for any purpose.
//
//  The author gratefully acknowleges the support of Dragon Systems, Inc., in
//  producing this work.

#ifndef SUBCLASS_DWA051500_H_
# define SUBCLASS_DWA051500_H_

# include "pyconfig.h"
# include "newtypes.h"
# include "objects.h"
# include "singleton.h"
# include <boost/utility.hpp>
# include "py.h"
# include "callback.h"

namespace py {

// A simple type which acts something like a built-in Python class instance.
class Instance : public PythonObject
{
 public:
    Instance(PyTypeObject* class_);
    ~Instance();

    // Standard Python functions.
    PyObject* repr();
    int compare(PyObject*);
    PyObject* str();
    long hash();
    PyObject* call(PyObject* args, PyObject* keywords);
    PyObject* getattr(const char* name, bool use_special_function = true);
    int setattr(const char* name, PyObject* value);

    // Mapping methods
    int length();
    PyObject* get_subscript(PyObject* key);
    void set_subscript(PyObject* key, PyObject* value);

    // Sequence methods
    PyObject* get_slice(int start, int finish);
    void set_slice(int start, int finish, PyObject* value);

    // Number methods
    PyObject* add(PyObject* other);
    PyObject* subtract(PyObject* other);
    PyObject* multiply(PyObject* other);
    PyObject* divide(PyObject* other);
    PyObject* remainder(PyObject* other);
    PyObject* divmod(PyObject* other);
    PyObject* power(PyObject*, PyObject*);
    PyObject* negative();
    PyObject* positive();
    PyObject* absolute();
    int nonzero();
    PyObject* invert();
    PyObject* lshift(PyObject* other);
    PyObject* rshift(PyObject* other);
    PyObject* do_and(PyObject* other);
    PyObject* do_xor(PyObject* other);
    PyObject* do_or(PyObject* other);
    int coerce(PyObject**, PyObject**);
    PyObject* as_int();
    PyObject* as_long();
    PyObject* as_float();
    PyObject* oct();
    PyObject* hex();

 private: // noncopyable, without the size bloat
    Instance(const Instance&);
    void operator=(const Instance&);

 private: // helper functions
    int setattr_dict(PyObject* value);
    
 private:
    Dict m_name_space;
};

template <class T> class MetaClass;

namespace detail {
  class ClassBase : public py::TypeObjectBase
  {
   public:
      ClassBase(PyTypeObject* meta_class, String name, Tuple bases, const Dict& name_space);
      Tuple bases() const;
      String name() const;
      Dict& dict();
      
      // Standard Python functions.
      PyObject* getattr(const char* name) const;
      int setattr(const char* name, PyObject* value);
      PyObject* repr() const;
      void add_base(Ptr base);

   protected:
      bool initialize_instance(Instance* instance, PyObject* args, PyObject* keywords);

   private: // virtual functions
      // Subclasses should override this to delete the particular instance type
      virtual void delete_instance(PyObject*) const = 0;

   private: // py::TypeObjectBase required interface implementation
      void instance_dealloc(PyObject*) const; // subclasses should not override this
      
   private:
      String m_name;
      Tuple m_bases;
      Dict m_name_space;
  };

  void enable_named_method(ClassBase* type_object, const char* name);
}

// A type which acts a lot like a built-in Python class. T is the instance type,
// so Class<Instance> is a very simple "class-alike".
template <class T>
class Class
    : public py::detail::ClassBase
{
 public:
    Class(MetaClass<T>* meta_class, String name, Tuple bases, const Dict& name_space);
    
    // Standard Python functions.
    PyObject* call(PyObject* args, PyObject* keywords);
    
 private: // Implement mapping methods on instances
    PyObject* instance_repr(PyObject*) const;
    int instance_compare(PyObject*, PyObject* other) const;
    PyObject* instance_str(PyObject*) const;
    long instance_hash(PyObject*) const;
    int instance_mapping_length(PyObject*) const;
    PyObject* instance_mapping_subscript(PyObject*, PyObject*) const;
    int instance_mapping_ass_subscript(PyObject*, PyObject*, PyObject*) const;

 private: // Implement sequence methods on instances
    int instance_sequence_length(PyObject*) const;
    PyObject* instance_sequence_item(PyObject* instance, int n) const;
    int instance_sequence_ass_item(PyObject* instance, int n, PyObject* value) const;
    PyObject* instance_sequence_slice(PyObject*, int start, int finish) const;
    int instance_sequence_ass_slice(PyObject*, int start, int finish, PyObject* value) const;

 private: // Implement number methods on instances
    PyObject* instance_number_add(PyObject*, PyObject*) const;
    PyObject* instance_number_subtract(PyObject*, PyObject*) const;
    PyObject* instance_number_multiply(PyObject*, PyObject*) const;
    PyObject* instance_number_divide(PyObject*, PyObject*) const;
    PyObject* instance_number_remainder(PyObject*, PyObject*) const;
    PyObject* instance_number_divmod(PyObject*, PyObject*) const;
    PyObject* instance_number_power(PyObject*, PyObject*, PyObject*) const;
    PyObject* instance_number_negative(PyObject*) const;
    PyObject* instance_number_positive(PyObject*) const;
    PyObject* instance_number_absolute(PyObject*) const;
    int instance_number_nonzero(PyObject*) const;
    PyObject* instance_number_invert(PyObject*) const;
    PyObject* instance_number_lshift(PyObject*, PyObject*) const;
    PyObject* instance_number_rshift(PyObject*, PyObject*) const;
    PyObject* instance_number_and(PyObject*, PyObject*) const;
    PyObject* instance_number_xor(PyObject*, PyObject*) const;
    PyObject* instance_number_or(PyObject*, PyObject*) const;
    int instance_number_coerce(PyObject*, PyObject**, PyObject**) const;
    PyObject* instance_number_int(PyObject*) const;
    PyObject* instance_number_long(PyObject*) const;
    PyObject* instance_number_float(PyObject*) const;
    PyObject* instance_number_oct(PyObject*) const;
    PyObject* instance_number_hex(PyObject*) const;
    
 private: // Miscellaneous "special" methods
    PyObject* instance_call(PyObject* instance, PyObject* args, PyObject* keywords) const;
    PyObject* instance_getattr(PyObject* instance, const char* name) const;
    int instance_setattr(PyObject* instance, const char* name, PyObject* value) const;

 private: // Implementation of py::detail::ClassBase required interface
    void delete_instance(PyObject*) const;
    
 private: // noncopyable, without the size bloat
    Class(const Class<T>&);
    void operator=(const Class&);
};

// The type of a Class<T> object.
template <class T>
class MetaClass
    : public Reprable<Callable<Getattrable<Setattrable<TypeObject<Class<T> > > > > >,
      boost::noncopyable
{
 public:
    MetaClass();

    // Standard Python functions.
    PyObject* call(PyObject* args, PyObject* keywords);
    
    struct TypeObject
        : Singleton<TypeObject, Callable<py::TypeObject<MetaClass> > >
    {
        TypeObject() : SingletonBase(&PyType_Type) {}
    };
};

//
// Member function implementations.
//
template <class T>
MetaClass<T>::MetaClass()
    : Properties(TypeObject::singleton())
{
} 

template <class T>
Class<T>::Class(MetaClass<T>* meta_class, String name, Tuple bases, const Dict& name_space)
    : py::detail::ClassBase(meta_class, name, bases, name_space)
{
}

template <class T>
void Class<T>::delete_instance(PyObject* instance) const
{
    delete Downcast<T>(instance);
}

template <class T>
PyObject* Class<T>::call(PyObject* args, PyObject* keywords)
{
    PyPtr<T> result(new T(this));
    if (!this->initialize_instance(result.get(), args, keywords))
        return 0;
    else
        return result.release();
}

template <class T>
PyObject* Class<T>::instance_repr(PyObject* instance) const
{
    return Downcast<T>(instance)->repr();
}

template <class T>
int Class<T>::instance_compare(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->compare(other);
}

template <class T>
PyObject* Class<T>::instance_str(PyObject* instance) const
{
    return Downcast<T>(instance)->str();
}

template <class T>
long Class<T>::instance_hash(PyObject* instance) const
{
    return Downcast<T>(instance)->hash();
}

template <class T>
int Class<T>::instance_mapping_length(PyObject* instance) const
{
    return Downcast<T>(instance)->length();
}

template <class T>
int Class<T>::instance_sequence_length(PyObject* instance) const
{
    return Downcast<T>(instance)->length();
}

template <class T>
PyObject* Class<T>::instance_mapping_subscript(PyObject* instance, PyObject* key) const
{
    return Downcast<T>(instance)->get_subscript(key);
}

template <class T>
PyObject* Class<T>::instance_sequence_item(PyObject* instance, int n) const
{
    Ptr key(to_python(n));
    return Downcast<T>(instance)->get_subscript(key.get());
}

template <class T>
int Class<T>::instance_sequence_ass_item(PyObject* instance, int n, PyObject* value) const
{
    Ptr key(to_python(n));
    Downcast<T>(instance)->set_subscript(key.get(), value);
    return 0;
}

template <class T>
int Class<T>::instance_mapping_ass_subscript(PyObject* instance, PyObject* key, PyObject* value) const
{
    Downcast<T>(instance)->set_subscript(key, value);
    return 0;
}

void adjust_slice_indices(PyObject* instance, int& start, int& finish);

template <class T>
PyObject* Class<T>::instance_sequence_slice(PyObject* instance, int start, int finish) const
{
    adjust_slice_indices(instance, start, finish);    
    return Downcast<T>(instance)->get_slice(start, finish);
}

template <class T>
int Class<T>::instance_sequence_ass_slice(PyObject* instance, int start, int finish, PyObject* value) const
{
    adjust_slice_indices(instance, start, finish);
    Downcast<T>(instance)->set_slice(start, finish, value);
    return 0;
}

template <class T>
PyObject* Class<T>::instance_call(PyObject* instance, PyObject* args, PyObject* keywords) const
{
    return Downcast<T>(instance)->call(args, keywords);
}

template <class T>
PyObject* Class<T>::instance_getattr(PyObject* instance, const char* name) const
{
    return Downcast<T>(instance)->getattr(name);
}


template <class T>
int Class<T>::instance_setattr(PyObject* instance, const char* name, PyObject* value) const
{
    return Downcast<T>(instance)->setattr(name, value);
}

template <class T>
PyObject* Class<T>::instance_number_add(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->add(other);
}

template <class T>
PyObject* Class<T>::instance_number_subtract(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->subtract(other);
}

template <class T>
PyObject* Class<T>::instance_number_multiply(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->multiply(other);
}

template <class T>
PyObject* Class<T>::instance_number_divide(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->divide(other);
}

template <class T>
PyObject* Class<T>::instance_number_remainder(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->remainder(other);
}

template <class T>
PyObject* Class<T>::instance_number_divmod(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->divmod(other);
}

template <class T>
PyObject* Class<T>::instance_number_power(PyObject* instance, PyObject* exponent, PyObject* modulus) const
{
    return Downcast<T>(instance)->power(exponent, modulus);
}

template <class T>
PyObject* Class<T>::instance_number_negative(PyObject* instance) const
{
    return Downcast<T>(instance)->negative();
}

template <class T>
PyObject* Class<T>::instance_number_positive(PyObject* instance) const
{
    return Downcast<T>(instance)->positive();
}

template <class T>
PyObject* Class<T>::instance_number_absolute(PyObject* instance) const
{
    return Downcast<T>(instance)->absolute();
}

template <class T>
int Class<T>::instance_number_nonzero(PyObject* instance) const
{
    return Downcast<T>(instance)->nonzero();
}

template <class T>
PyObject* Class<T>::instance_number_invert(PyObject* instance) const
{
    return Downcast<T>(instance)->invert();
}

template <class T>
PyObject* Class<T>::instance_number_lshift(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->lshift(other);
}

template <class T>
PyObject* Class<T>::instance_number_rshift(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->rshift(other);
}

template <class T>
PyObject* Class<T>::instance_number_and(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->do_and(other);
}

template <class T>
PyObject* Class<T>::instance_number_xor(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->do_xor(other);
}

template <class T>
PyObject* Class<T>::instance_number_or(PyObject* instance, PyObject* other) const
{
    return Downcast<T>(instance)->do_or(other);
}

template <class T>
int Class<T>::instance_number_coerce(PyObject* instance, PyObject** x, PyObject** y) const
{
    return Downcast<T>(instance)->coerce(x, y);
}

template <class T>
PyObject* Class<T>::instance_number_int(PyObject* instance) const
{
    return Downcast<T>(instance)->as_int();
}

template <class T>
PyObject* Class<T>::instance_number_long(PyObject* instance) const
{
    return Downcast<T>(instance)->as_long();
}

template <class T>
PyObject* Class<T>::instance_number_float(PyObject* instance) const
{
    return Downcast<T>(instance)->as_float();
}

template <class T>
PyObject* Class<T>::instance_number_oct(PyObject* instance) const
{
    return Downcast<T>(instance)->oct();
}

template <class T>
PyObject* Class<T>::instance_number_hex(PyObject* instance) const
{
    return Downcast<T>(instance)->hex();
}

namespace detail {
  inline Dict& ClassBase::dict()
  {
      return m_name_space;
  }

  inline Tuple ClassBase::bases() const
  {
      return m_bases;
  }
}

template <class T>
PyObject* MetaClass<T>::call(PyObject* args, PyObject* /*keywords*/)
{
    PyObject* name;
    PyObject* bases;
    PyObject* name_space;
    
    if (!PyArg_ParseTuple(args, const_cast<char*>("O!O!O!"),
                          &PyString_Type, &name,
                          &PyTuple_Type, &bases,
                          &PyDict_Type, &name_space))
    {
        return 0;
    }
    
    return as_object(
        new Class<T>(this, String(Ptr(name, Ptr::borrowed)),
                  Tuple(Ptr(bases, Ptr::borrowed)),
                  Dict(Ptr(name_space, Ptr::borrowed)))
        );
}

namespace detail {
  const String& setattr_string();
  const String& getattr_string();
  const String& delattr_string();

  inline String ClassBase::name() const
  {
      return m_name;
  }
}


} // namespace py
#endif