Traceability in Lua Functions

Versión en español de esta publicación.
This weekend I’ve been working on some lua scripts with which I was having some problems debugging the flow of the code. I decided to write a small function in order to print some information of the current function flow and parameter values.

The first function presented below receives the current function name as first parameter and a parameter list that is used to create a nice formated flow function string to print. The second function is an example on how to use the first function to print the flow.

local function debug_print_trac(func, ...)
    local res = func .. "( ";
    for i,v in ipairs(arg) do
        res = res .. tostring(v) .. " ";
    end
    res = res .. " )";
    debug_print(res);
end
 
local function set_monitor(monitor)
    debug_print_trac(debug.getinfo(1, "n").name, monitor);
    if (monitor == "principal") then
        set_window_position(0,0);
    else
        set_window_position(2561,0);
    end
end

And here are some printed results of function calls. We have our current flow functions and its parameters values printed.

set_top( false  )
Window Name: The Linux Programming Interface
Application name: Document Viewer
max_in( principal 4 false  )
set_monitor( principal  )

¡Cheers!
-Yohan