Re: A Question of Style

[HyperHacker <hyperhacker@...>]

On Tue, Nov 29, 2011 at 20:43, jiang yu <yu.jiang.163@gmail.com> wrote:
> That's right, but, not simple.
>
> 2011/11/30 HyperHacker <hyperhacker@gmail.com>:
>> On Tue, Nov 29, 2011 at 10:18, jiang yu <yu.jiang.163@gmail.com> wrote:
>>> I prefer 2)
>>> 1. It is simpler than 1)
>>> 2. If there is bug in 2), you can correct it and just dofile() —— no
>>> need restart the program.
>>>
>>> 2011/11/26 Marc Balmer <marc@msys.ch>:
>>>> Hi
>>>>
>>>> I have a stylistic question wrt/ calling Lua "callbacks" from a C
>>>> program.  I see two obvious approaches:
>>>>
>>>> 1) Lua code registers callbacks explicitely using a RegisterCallback
>>>> function that is provided by the C program; the C program later calls
>>>> the callback function when one is registered.
>>>>
>>>> 2) Lua code does not register callbacks, but the callbacks must be
>>>> functions with a certain name, e.g. "MouseMovedCallback"; C code will
>>>> then see if a function with the correct name is available in the Lua
>>>> state, and if so, call it.
>>>>
>>>> Are there advantages of one approach over the other?  Are there other
>>>> approaches?  If you also use callback written in Lua, which you call
>>>> from C, I'd like you to share your opinion (and/or experience).
>>>>
>>>> I experienced with both forms, I am unsure for which form to go...
>>>>
>>>> Thanks,
>>>> Marc
>>>>
>>>
>>
>> You can do that with method 1 too, by just having the script
>> unregister and reregister its handlers at startup.
>>
>> --
>> Sent from my toaster.
>>
>

Seems simple enough to me. Just add a couple lines at the end:
UnregisterCallback('OnOpen', my_on_open_callback)
RegisterCallback('OnOpen', my_on_open_callback)

UnregisterCallback just needs to fail gracefully if given a callback
that isn't registered.

-- 
Sent from my toaster.