Lua Quick Start Guide

Return ("r")

The final type of hook is a return hook. Return hooks get executed every time a function returns, that is, when the return keyword is encountered. To subscribe to a return event, provide debug.sethook with two arguments: the handler function, and the "r" string.

The handler function takes only one argument, a string constant with the "return" value. This callback is similar to the function callback:

function Normalize(x, y, z)  local dot = x * x + y * y + z * z  if dot == 0 then    return nil  end  local len = math.sqrt(dot)  return {    x = x / len,    y = y / len,    z = z / len  }endfunction trace(event)  local info = debug.getinfo(2)  if info.what == "Lua" then    print ("event: " .. event)    print (" function: " .. info.name) print (" defined on: ...