Re: Detecting read or write access in __index metamethod

[Marc Balmer <marc@...>]

Am 15.12.10 17:09, schrieb Luiz Henrique de Figueiredo:
>> Is there a way to detect in an __index meta-method, written in C, if the
>> access is for reading or writing a value?  I.e. to distinguish between
>>
>> a.b.c = 42
>>
>> and
>>
>> local answer = a.b.c
> 
> Perhaps you mean this? http://lua-users.org/wiki/AutomagicTables

Similar, yes.  I successfully created it in C to access ClearSilver HDF
structures, however

a.b.c.d = "a.b and a.b.c are automatically created"

this part works. But when I access a not-yet existing valued, e.g.

local n = a.b.x.y

Then I want to get nil.  Unfortunately what happens, is that a.b and
a.b.x, a.b.x.y get created.

So write access should create the whole chain, whereas read access
should not.