[Ovmsdev] Duktape Persistent Function References

[Mark Webb-Johnson]

Wow. That would have taken me hours to work out. Thanks.

Any idea why it compiled in master, but not in for-v3.3?

Regards, Mark.

> On 25 Sep 2020, at 9:10 PM, Michael Balzer <dexter at expeedo.de> wrote:
> 
> Mark,
> 
> the issue is, there are ambiguous overloads of these methods in their classes, and the compiler doesn't know which one to pick.
> 
> - https://stackoverflow.com/questions/10111042/wrap-overloaded-function-via-stdfunction <https://stackoverflow.com/questions/10111042/wrap-overloaded-function-via-stdfunction>
> - https://stackoverflow.com/questions/30393285/stdfunction-fails-to-distinguish-overloaded-functions <https://stackoverflow.com/questions/30393285/stdfunction-fails-to-distinguish-overloaded-functions>
> 
> I prefer to keep my command stub names distinguished from their implementation counterparts, but apparently that doesn't apply to all of us ;-)
> 
> Coming C++ versions may be smart enough to deduce the method to pick from the expected signature.
> 
> For now, the compiler needs a hint here. I've added two preprocessor macros to make these hints readable.
> 
> Regards,
> Michael
> 
> 
> Am 25.09.20 um 08:07 schrieb Mark Webb-Johnson:
>> @Michael,
>> 
>> I’ve tried merging this (along with all the other recent changes in master) into the for-v3.3 branch, but am now getting compilation errors. The two files with issues are:
>> 
>> components/retools_testerpresent/src/retools_testerpresent.cpp
>> components/vehicle_mgev/src/vehicle_mgev.cpp
>> 
>> Both in the RegisterCommand function call with the static class member function as a parameter. Not sure if that new way is used elsewhere?
>> 
>> Example compiler output is:
>> 
>> CXX build/retools_testerpresent/src/retools_testerpresent.o
>> .../components/retools_testerpresent/src/retools_testerpresent.cpp: In constructor 'OvmsReToolsTesterPresentInit::OvmsReToolsTesterPresentInit()':
>> .../components/retools_testerpresent/src/retools_testerpresent.cpp:140:5: error: no matching function for call to 'OvmsCommand::RegisterCommand(const char [6], const char [48], <unresolved overloaded function type>, const char [23], int, int)'
>>      );
>>      ^
>> 
>> CXX build/vehicle_mgev/src/vehicle_mgev.o
>> .../components/vehicle_mgev/src/vehicle_mgev.cpp: In constructor 'OvmsVehicleMgEv::OvmsVehicleMgEv()':
>> .../components/vehicle_mgev/src/vehicle_mgev.cpp:143:5: error: no matching function for call to 'OvmsCommandApp::RegisterCommand(const char [8], const char [15], <unresolved overloaded function type>)'
>>      );
>>      ^mand(const char* name, const char* title,
>>                   ^
>> 
>> I tried for a while, but can’t see what is wrong. Perhaps some missing header file? Anyway, I’ve committed the merge of master into for-v3.3 (even though it doesn’t compile) and just commented out those registrations in my local copy.
>> 
>> Can you help?
>> 
>> Thanks, Mark.
>> 
>>> On 12 Sep 2020, at 5:12 AM, Michael Balzer <dexter at expeedo.de <mailto:dexter at expeedo.de>> wrote:
>>> 
>>> Mark,
>>> 
>>> Am 11.09.20 um 18:11 schrieb Michael Balzer:
>>>>> I agree it is not necessary; my suggestion is purely to clean it up
>>>>> and enhance functionality. The problem at the moment is that
>>>>> OvmsCommand execute callbacks can only be to function callbacks (not
>>>>> objects). It doesn’t even use the c++ bind function callback
>>>>> mechanism (like notification, etc, for example). It is what it is,
>>>>> and changing now is very hard.
>>>> 
>>>> That slipped my attention, but upgrading OvmsCommand to accept any
>>>> function type should be simply changing m_execute and m_validate to
>>>> std::function, or do I miss something?
>>> 
>>> Just did this locally, works perfectly. Shall I push the change or have
>>> you begun working on ovms_command?
>>> 
>>> If so, it's really just exchanging the function signatures for these types:
>>> 
>>> typedef std::function<void(int, OvmsWriter*, OvmsCommand*, int, const
>>> char* const*)> OvmsCommandExecuteCallback_t;
>>> typedef std::function<int(OvmsWriter*, OvmsCommand*, int, const char*
>>> const*, bool)> OvmsCommandValidateCallback_t;
>>> 
>>> Patch attached.
>>> 
>>> Regards,
>>> Michael
>>> 
>>> -- 
>>> Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
>>> Fon 02333 / 833 5735 * Handy 0176 / 206 989 26
>>> 
>>> <ovmscommand.patch>_______________________________________________
>>> OvmsDev mailing list
>>> OvmsDev at lists.openvehicles.com <mailto:OvmsDev at lists.openvehicles.com>
>>> http://lists.openvehicles.com/mailman/listinfo/ovmsdev <http://lists.openvehicles.com/mailman/listinfo/ovmsdev>
>> 
>> 
>> 
>> _______________________________________________
>> OvmsDev mailing list
>> OvmsDev at lists.openvehicles.com <mailto:OvmsDev at lists.openvehicles.com>
>> http://lists.openvehicles.com/mailman/listinfo/ovmsdev <http://lists.openvehicles.com/mailman/listinfo/ovmsdev>
> 
> -- 
> Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
> Fon 02333 / 833 5735 * Handy 0176 / 206 989 26
> _______________________________________________
> OvmsDev mailing list
> OvmsDev at lists.openvehicles.com
> http://lists.openvehicles.com/mailman/listinfo/ovmsdev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvehicles.com/pipermail/ovmsdev/attachments/20200925/69bf3ab5/attachment-0002.htm>