Eval a Lua expression

[Eugen-Andrei Gavriloaie <shiretu@...>]

Hi,

Sorry if this is a stupid question.  But either I can't find the  
answer in the docs because of a "selective" blindness or it's not so  
obvious (I'm a newbie in Lua world). So here is the question:


Suppose we have a Lua file like this:

-- begin cut --
applications=
{
        {
                name="selector",
                description="Application for selecting the rest of  
the applications",
                database=
                {
                        type="postgresql",
                        connectingString="postgresql connecting  
string....",
                        workersCount=10
                }
        },
        {
                name="simpleLive",
                description="Sample application",
                database=
                {
                        type="mysql",
                        connectingString="postgresql connecting  
string....",
                        workersCount=10
                }

        }
}
-- end cut --

This is in fact a part of a configuration file. I can load it, extract  
all the data I need from it using lua_gettable and such, but my c++  
code is looking very ugly. Because I keep pushing and popping from the  
stack and other things like that. Is there a method of evaluating an  
expression in the present lua context? Here is what I want:

lua_evaluate_expression(L,"applications[2].type"); // expect to find  
`mysql` string pushed into the stack after this call

or

lua_evaluate_expression(L,"#applications"); // expect to find value of  
2 pushed into the stack after this call

This is supposed to push the result of the expression into the stack.  
After that, I will pop it up from there and do whatever I want with  
it. The end resulting c++ code would be much cleaner and easy to  
understand.


Thank you