An extensible math expression parser with plug-ins

	
// MTFirstPlugin.h : Declaration of the CMTFirstPlugin

#ifndef __MTFIRSTPLUGIN_H_
#define __MTFIRSTPLUGIN_H_

#include "resource.h"       // main symbols
#import "..\MTPluginIDL\MTPluginIDL.tlb" raw_interfaces_only, raw_native_types, no_namespace, named_guids 
#include <vector>

/////////////////////////////////////////////////////////////////////////////
// CMTFirstPlugin
class ATL_NO_VTABLE CMTFirstPlugin : 
	public CComObjectRootEx<CComMultiThreadModel>,
	public CComCoClass<CMTFirstPlugin, &CLSID_MTFirstPlugin>,
	public ISupportErrorInfo,
	public IDispatchImpl<IMTFirstPlugin, &IID_IMTFirstPlugin, &LIBID_MTPLUGINDEMOLib>,
	public IDispatchImpl<IMTPlugin, &IID_IMTPlugin, &LIBID_MTPLUGINIDLLib>
{
public:
	CMTFirstPlugin()
	{
		m_pUnkMarshaler = NULL;
		initPlugin();
	}

	~CMTFirstPlugin();

DECLARE_REGISTRY_RESOURCEID(IDR_MTFIRSTPLUGIN)
DECLARE_GET_CONTROLLING_UNKNOWN()

DECLARE_PROTECT_FINAL_CONSTRUCT()

BEGIN_COM_MAP(CMTFirstPlugin)
	COM_INTERFACE_ENTRY(IMTFirstPlugin)
//DEL 	COM_INTERFACE_ENTRY(IDispatch)
	COM_INTERFACE_ENTRY(ISupportErrorInfo)
	COM_INTERFACE_ENTRY_AGGREGATE(IID_IMarshal, m_pUnkMarshaler.p)
	COM_INTERFACE_ENTRY2(IDispatch, IMTFirstPlugin)
	COM_INTERFACE_ENTRY(IMTPlugin)
END_COM_MAP()

	HRESULT FinalConstruct()
	{
		return CoCreateFreeThreadedMarshaler(
			GetControllingUnknown(), &m_pUnkMarshaler.p);
	}

	void FinalRelease()
	{
		m_pUnkMarshaler.Release();
	}

	CComPtr<IUnknown> m_pUnkMarshaler;

// ISupportsErrorInfo
	STDMETHOD(InterfaceSupportsErrorInfo)(REFIID riid);

// IMTFirstPlugin
public:
// IMTPlugin
	STDMETHOD(getNbConsts)(INT * pNbConsts);	
	STDMETHOD(getConst)(INT id, BSTR * name, DOUBLE * pVal);	
	STDMETHOD(getNbFuncs)(INT * pNbFuncs);	
	STDMETHOD(getFuncSymbol)(INT id, BSTR * symbol);
	STDMETHOD(getFuncHelpString)(INT id, BSTR * helpString);
	STDMETHOD(getFuncDescription)(INT id, BSTR * description);
	STDMETHOD(isFuncConstant)(INT id, INT * pConstant);
	STDMETHOD(getFuncNbArgs)(INT id, INT * pNbArgs);
	STDMETHOD(evaluateFunc)(INT id, INT nbArgs, DOUBLE * pArg, DOUBLE * pResult);	
	STDMETHOD(getNbOps)(INT * pNbOps);	
	STDMETHOD(getOpPrecedence)(INT id, INT * pPrecedence);
	STDMETHOD(isOpConstant)(INT id, INT * pConstant);	
	STDMETHOD(getOpSymbol)(INT id, BSTR * symbol);
	STDMETHOD(getOpHelpString)(INT id, BSTR * helpString);
	STDMETHOD(getOpDescription)(INT id, BSTR * description);
	STDMETHOD(isOneArgOp)(INT id, INT * pOneArg);
	STDMETHOD(evaluateOp)(INT id, INT nbArgs, DOUBLE * pArg, DOUBLE * pResult);
	
private:

	// create function and operator objects
	void initPlugin();

	// add a constant
	void addConst(LPCTSTR name, double value);

private:

	struct SConstant
	{
		CComBSTR name;
		double value;
	};

	std::vector<class IMathFunction*> m_funcs;
	std::vector<class IMathOperator*> m_ops;
	std::vector<SConstant> m_consts;

};

#endif //__MTFIRSTPLUGIN_H_