问获取lua中函数的参数名称

EN

function PrintVariable(name)
  -- default to showing the global with that name, if any
  local value = _G[name]

  -- see if we can find a local in the caller's scope with that name
  for i=1,math.huge do
    local localname, localvalue = debug.getlocal(2,i,1)
    if not localname then
      break -- no more locals to check
    elseif localname == name then
      value = localvalue
    end
  end

  if value then
    print(string.format("%s = %s", name, tostring(value)))
  else
    print(string.format("No variable named '%s' found.", name))
  end
end

PrintVariable('MyVariable')

function PrintVariable(value)
  local name

  -- see if we can find a local in the caller's scope with the given value
  for i=1,math.huge do
    local localname, localvalue = debug.getlocal(2,i,1)
    if not localname then
      break
    elseif localvalue == value then
      name = localname
    end
  end

  -- if we couldn't find a local, check globals
  if not name then
    for globalname, globalvalue in pairs(_G) do
      if globalvalue == value then
        name = globalname
      end
    end
  end

  if name then
    print(string.format("%s = %s", name, tostring(value)))
  else
    print(string.format("No variable found for the value '%s'.", tostring(value)))
  end
end

function PrintVariable(VariableToPrint)
  --we can use debug.getinfo() to determine the name 'VariableToPrint'
  --we cannot determine the name 'MyVariable' without some really convoluted stuff (see comment by VBRonPaulFan on his own answer)
  print(VariableToPrint);
end

MyVariable = 4
PrintVariable(MyVariable)

x = 4
MyVariable = x
MyOtherVariable = x
x = nil

PrintVariable(MyVariable)

PrintVariable("StringLiteral")

function a_func(arg1, asdf)
    -- if this function doesn't use an argument... it shows up as (*temporary) in 
    -- calls to debug.getlocal() because they aren't used...
    if arg1 == "10" then end
    if asdf == 99 then end
    -- does stuff with arg1 and asdf?
end

-- just a function to dump variables in a user-readable format
function myUnpack(tbl)
    if type(tbl) ~= "table" then
        return ""
    end

    local ret = ""
    for k,v in pairs(tbl) do
        if tostring(v) ~= "" then
            ret = ret.. tostring(k).. "=".. tostring(v).. ", "
        end
    end
    return string.gsub(ret, ", $", "")
end

function hook()
    -- passing 2 to to debug.getinfo means 'give me info on the function that spawned 
    -- this call to this function'. level 1 is the C function that called the hook.
    local info = debug.getinfo(2)
    if info ~= nil and info.what == "Lua" then
        local i, variables = 1, {""}
        -- now run through all the local variables at this level of the lua stack
        while true do
            local name, value = debug.getlocal(2, i)
            if name == nil then
                break
            end
            -- this just skips unused variables
            if name ~= "(*temporary)" then
                variables[tostring(name)] = value
            end
            i = i + 1
        end
            -- this is what dumps info about a function thats been called
        print((info.name or "unknown").. "(".. myUnpack(variables).. ")")
    end
end

-- tell the debug library to call lua function 'hook 'every time a function call
-- is made...
debug.sethook(hook, "c")

-- call a function to try it out...
a_func("some string", 2012)

a_func(asdf=2012, arg1=some string)