Re: c api to create local or upvalues?

[Javier Guerra Giraldez <javier@...>]

On Wed, Aug 3, 2011 at 3:01 PM, Hao Wu <wuhao.wise@gmail.com> wrote:
> I am trying to do something like "this" pointer in c++.

in most OO languages (C++ included), the 'this', 'self', 'me' pointer
is just a parameter.  sometimes explicit (C, Python, Lua), sometimes
invisible (C++, Lua).

In fact, the 'OO style' functions in Lua is just a different syntax to
make an invisible 'self' parameter, but it's totally equivalent to
doing it explicitly.

-- method definition
function obj:meth(arg) .... end
-- calling a method
obj:meth(arg)

is the same as:

-- method definition
function obj.meth(self,arg) ... end
-- calling a method
obj.meth(obj, arg)

that's why you can use either:

string.format (sss, v1, v2, ....)
or
sss:format (v1, v2, ...)


tl;dr:  just add a 'self' first argument (can be named anything, but
'self' is more idiomatic in Lua than 'this')

-- 
Javier