I use luaVM in another programming language (Vala) and want to pass the code from vala to lua so that lua returns the result of executing this code as a string.
> s2="print (5+5)"
> s2
print (5+5)
> loadstring(s2)
function: 0x55834153f080
> func = loadstring(s2)
> func()
10
tried a lot of things, but I did not succeed, that is, I need instead of 10 was a variable of type string containing 10. So I could do vm.to_string(-1) of Vala and to obtain "10"
As Egor stated you can cast your result to a string before returning it using tostring.
I would also add you may want to use dostring not loadstring.
A load function in lua means to compile and not run the chunk, instead it returns a function when called will run the chunk.(loadfile, loadstring)
A do function will compile and run the contents.(dofile, dostring)
The details can be found here: Lua: 8 – Compilation, Execution, and Errors
Like dofile, loadfile also loads a Lua chunk from a file, but it does not run the chunk. Instead, it only compiles the chunk and returns the compiled chunk as a function.
This section speak more directly to loadfile but the page covers loadstring.
if dostring is not defined it can be like so:
function dostring(s)
return assert(loadstring(s))()
end
If you are using a version of lua later then 5.1 loadstring becomes load
return tostring dostring("..inputCode..") should look something like this return tostring(dostring("..inputCode..") or 'nil'). you are missing () from your tostring function around the dostringdostring("..inputCode..") or 'nil' the or nil returns a default value to the tostring function if the inputCode does not return a value. This will prevent an errors from tostring when this happens. the value could be anything it does not need to be nil it could be 0 if that is better
return tostring(5+5)local str = loadstring(s2)().