module_definition.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
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 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_UTIL_MODULE_DEFINITION_H
#define LASS_GUARDIAN_OF_INCLUSION_UTIL_MODULE_DEFINITION_H
 
#include "python_common.h"
#include "pyobject_plus.h"
#include "../util/callback_0.h"
#include "../util/callback_1.h"
 
namespace lass
{
namespace python
{
 
/** @defgroup ModuleDefinition Module Definitions
 *  @brief Defining Python modules from C++ with classes, functions, and enums.
 *
 *  This module provides helper classes and macros to define Python modules that can contain
 *  C++ classes, functions, enums, and other objects exported to Python.
 * 
 *
 *  ### Module Components
 * 
 *  A Python module can contain:
 * 
 *  - **Functions**: C++ functions exported with various signatures
 *  - **Classes**: C++ classes exported as Python classes
 *  - **Enums**: C++ enums exported as Python enum types
 *  - **Objects**: Arbitrary Python objects (constants, instances, etc.)
 *  - **Values**: Simple values like integers and strings
 *
 *
 *  ### Usage Overview
 * 
 *  To create a Python module, you typically use macros that work with ModuleDefinition:
 *  
 *  ```cpp
 *  // Define module
 *  PY_DECLARE_MODULE_NAME_DOC(mymodule, "mymodule", "My example module")
 *  
 *  // Add functions
 *  PY_MODULE_FUNCTION(mymodule, myFunction)
 *  
 *  // Add classes
 *  PY_MODULE_CLASS(mymodule, MyClass)
 *  
 *  // Add enums
 *  PY_MODULE_ENUM(mymodule, MyEnum)
 *  
 *  // Create module entrypoint for Python extension
 *  PY_MODULE_ENTRYPOINT(mymodule)
 *  ```
 * 
 *  The ModuleDefinition class is typically not used directly. Instead, use the provided
 *  macros in pyobject_macros.h that work with ModuleDefinition instances.
 *
 *  @ingroup Python
 */
 
class EnumDefinitionBase;
 
/** Definition of a Python module.
 *
 *  Holds the definition of a Python module and can create the module by calling inject().
 *  This class manages all components that make up a Python module: functions, classes,
 *  enums, and other objects.
 *
 *  The module definition accumulates all components during the program initialization
 *  phase, then creates the actual Python module when inject() is called.
 *
 *  This class is typically not used directly by user code. Use the provided
 *  macros in pyobject_macros.h that work with ModuleDefinition instances.
 *
 *  @ingroup ModuleDefinition
 */
class LASS_PYTHON_DLL ModuleDefinition: util::NonCopyable
{
public:
    /** Callback type for pre-injection hooks (called before module creation). */
    typedef util::Callback0 TPreInject;
    
    /** Callback type for post-injection hooks (called after module creation with module object). */
    typedef util::Callback1<PyObject*> TPostInject;
 
    /** Construct module definition with name and optional documentation.
     *  @param name Python module name (will be copied and stored internally)
     *  @param doc Optional module docstring (will be copied and stored internally, or nullptr)
     */
    ModuleDefinition(const char* name, const char* doc = 0);
    /** Get the module name. */
    const char* name() const { return name_.get(); }
    
    /** Set the module name.
     *  @param name New module name (will be copied and stored internally)
     */
    void setName(const char* name);
    
    /** Get the module documentation string. */
    const char* doc() const { return doc_.get(); }
    
    /** Set the module documentation string.
     *  @param doc New docstring (will be copied and stored internally, or nullptr)
     */
    void setDoc(const char* doc);
    
    /** Get the Python module object (available after inject() has been called). */
    PyObject* module() const { return module_; }
 
    /** Set callback to be executed before module injection.
     *  Useful for performing setup tasks before the module is created.
     *  @param callback Function to call before injection
     */
    void setPreInject(const TPreInject& callback);
    
    /** Set callback to be executed after module injection.
     *  Useful for performing additional setup on the created module.
     *  @param callback Function to call with the module object after injection
     */
    void setPostInject(const TPostInject& callback);
 
    /** Add a function dispatcher to the module.
     *  Used internally by function export macros to register C++ functions.
     *  @param dispatcher Function dispatcher for overload resolution
     *  @param name Python function name
     *  @param doc Function documentation string
     *  @param overloadChain Reference to overload chain for this function name
     */
    void addFunctionDispatcher(PyCFunction dispatcher, const char* name, const char* doc, PyCFunction& overloadChain);
    
    /** Add a class definition to the module.
     *  The class will be created and added when the module is injected.
     *  @param classDef Class definition containing class export information
     */
    void addClass(impl::ClassDefinition& classDef);
    
    /** Add an enum definition to the module.
     *  The enum type will be created and added when the module is injected.
     *  @param enumDef Enum definition containing enum export information
     */
    void addEnum(EnumDefinitionBase* enumDef);
    
    /** Add an arbitrary Python object to the module.
     *  The object will be added directly to the module namespace.
     *  @param object Python object to add
     *  @param name Name for the object in the module namespace
     */
    void addObject(PyObject* object, const char* name);
    
    /** Add a long integer constant to the module.
     *  @param object Long value to add as module constant
     *  @param name Name for the constant in the module namespace
     */
    void addLong(long object, const char* name);
    
    /** Add a string constant to the module.
     *  @param object String value to add as module constant
     *  @param name Name for the string in the module namespace
     */
    void addString(const char* object, const char* name);
 
    /** Inject a long integer directly into an already created module.
     *  This is for immediate injection, unlike addLong() which defers until inject().
     *  @param name Name for the constant in the module namespace
     *  @param value Long value to inject
     */
    void injectLong(const char* name, long value);
    
    /** Inject a string directly into an already created module.
     *  This is for immediate injection, unlike addString() which defers until inject().
     *  @param name Name for the string in the module namespace
     *  @param value String value to inject
     */
    void injectString(const char* name, const char* value);
    
    /** Inject an arbitrary object directly into an already created module.
     *  This is for immediate injection, unlike addObject() which defers until inject().
     *  @param object Object to inject (will be converted to Python object)
     *  @param name Name for the object in the module namespace
     */
    template <typename T>
    void injectObject(T&& object, const char* name)
    {
        PyModule_AddObject(module_, name, lass::python::pyBuildSimpleObject( std::forward<T>(object) ));
    }
 
    /** Inject a class definition directly into an already created module.
     *  @param classDef Class definition to inject
     *  @return true on success, false on failure
     */
    bool injectClass(impl::ClassDefinition& classDef);
    
    /** Create and inject the Python module with all accumulated definitions.
     *  This method should typically not be called directly. Use module registration
     *  macros which call this at the appropriate time during Python initialization.
     *  @return The created Python module object
     */
    PyObject* inject();
private:
    typedef std::unique_ptr<char[]> TScopedCString;
    typedef std::vector<impl::ClassDefinition*> TClassDefs;
    typedef std::vector<EnumDefinitionBase*> TEnumDefs;
    typedef std::vector<PyMethodDef> TMethods;
    struct NamedObject
    {
        TScopedCString name;
        PyObject* object;
    };
    struct LongObject
    {
        TScopedCString name;
        long object;
    };
    struct StringObject
    {
        TScopedCString name;
        TScopedCString object;
    };
    typedef std::vector<NamedObject*> TObjects;
    typedef std::vector<LongObject*> TLongObjects;
    typedef std::vector<StringObject*> TStringObjects;
 
    /** Implementation of module injection process. */
    PyObject* doInject();
 
    TClassDefs classes_;
    TEnumDefs enums_;
    TMethods methods_;
    TObjects objects_;
    TLongObjects longObjects_;
    TStringObjects stringObjects_;
    TScopedCString name_;
    TScopedCString doc_;
    TPreInject preInject_;
    TPostInject postInject_;
    PyObject* module_;
    PyModuleDef def_;
    bool isInjected_;
};
 
}
}
 
#endif