C++ MSG_MAP marcro -> Mixin

[Daniel Keep]

BLS wrote:
> BLS schrieb:
>> Hi,
>> MFC and wxWidgets are supporting MESSAGEMAPS macros. I would like to
>> port them to D.
>>
>> class CMsg
>> {
>> public:
>>
>>     virtual BOOL NewMsgProc(HWND hWnd, UINT uID, WPARAM wParam, LPARAM
>> lParam,LRESULT lResult)
>>     {
>>         return FALSE;
>>     }
>> };
>>
>> Okay, here iy goes ....
>> #define BEGIN_MSG_MAP() \
>> public: \
>>     virtual BOOL NewMsgProc(HWND hWnd, UINT uID, WPARAM wParam, LPARAM
>> lParam,LRESULT& lResult) \
>>     { \
>>        #define ON_MESSAGE(Msg, vfunc) \
>>     if(uID == Msg) \
>>     { \
>>         vfunc(uID, wParam, lParam); \
>>         lResult = 0; \
>>         return TRUE; \
>>     }
>>
>> #define ON_MESSAGE_RANGE(MsgF, MsgL, vfunc) \
>>     if(uID >= MsgF && uID <= MsgL) \
>>     { \
>>         lResult=vfunc(uID, wParam, lParam); \
>>         return TRUE; \
>>     }
>>
>> #define ON_COMMAND_CONTROL(iControl, iEvent, vfunc) \
>>     if(uID == WM_COMMAND && iControl == LOWORD(wParam) && iEvent ==
>> HIWORD(wParam)) \
>>     { \
>>         vfunc(HIWORD(wParam), LOWORD(wParam), (HWND)lParam); \
>>         lResult = 0; \
>>         return TRUE; \
>>     }
>>
>> and so on....
>>
>> Is it possible to replace this C++ Macros with D2 Mixins and compile
>> time manipulation of strings ?
>> How ?
>> Thanks, Bjoern
> 
> And I really wonder myself how to (probabely) replace this stuff using
> Tango's Signal Slot implementation.... but I guess I miss something;

With enough CTFE, you could do it.  I've actually been thinking about
making a generator ctfe compiler (but haven't got *any* free time at the
moment).

If I were doing this, I'd probably try something along these lines:

mixin(wxMsgMap(`
	on(id1) handler1;
	on(id2) handler2;
	on(id3..id6) handler3;
`));

Parsing that shouldn't be too difficult.  Of course, there are other
ways of constructing this:

mixin wxMsgMap!(
    OnMessage!(id1, handler1),
    OnMessage!(id2, handler2),
    OnMessage!(id3, id6, handler3)
);

Where wxMsgMap takes a tuple of templated OnMessage structs.

Just some ideas.

	-- Daniel