lua - get the list of parameter names of a function, from outside the function

Question

I'm generating some (non-html) documentation for a Lua library that I developed. I will generate the documentation by hand, but I'd appreciate some kind of automation if possible (i.e. generating skeletons for each function so I can fill them in)

I'd like to know if there's a way for lua to know the names of the parameters that a function takes, from outside it.

For example, is there a way to do this in Lua?

function foo(x,y)
  ... -- any code here
end

print( something ... foo ... something)
-- expected output: "x", "y"

Thanks a lot.

Answer 1

Take a look at debug.getinfo, but you probably need a parser for this task. I don't know of any way to fetch the parameters of a function from within Lua without actually running the function and inspecting its environment table (see debug.debug and debug.getlocal).

Answer 2

Take a look at the luadoc utility. It is sort of like Doxygen, but for Lua. It is intended to allow the documentation to be written in-line with the source code, but it could certainly be used to produce a template of the documentation structure to be fleshed out separately. Of course, the template mechanism will leave you with a maintenance issue down the road...

Answer 3

Try my bytecode inspector library. In Lua 5.2 you'll be able to use debug.getlocal.