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- Subject: Re: A Question of Style
- From: Rebel Neurofog <rebelneurofog@...>
- Date: Mon, 28 Nov 2011 13:49:32 +0300
On Mon, Nov 28, 2011 at 2:03 PM, Jerome Vuarand
> 2011/11/26 Rebel Neurofog <email@example.com>:
>> On Sat, Nov 26, 2011 at 5:03 PM, Marc Balmer <firstname.lastname@example.org> wrote:
>>> 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...
>> I prefer the first case.
>> A function may contain also upvalues.
>> Here's the code:
>> local desktop = widget_system.create_desktop ()
>> -- Case 1
>> input.set_mouse_handler (desktop.mouse_move)
>> -- Case 2
>> function mouse_move_handler (dx, dy)
>> desktop.mouse_move (dx, dy) -- note, there's no ":" here
> AFAICT there is no difference between the two methods with regards to
> upvalues. Since the function is not a method, the second case can be
> better written as:
> -- Case 2
> mouse_move_handler = desktop.mouse_move
You make me feel old and stupid:(
In fact Case 1 is
REGISTY["some_name"] = some_value
whereas Case 2 is
GLOBALS["some_name"] = some_value
No difference but namespacing.