debugstackwithname.lua

  do
    local err_fmt = "bad argument #%s to '%s' (%s expected, got %s)"
    
    local function checktypelist(t,a1,...)
      if a1 then
        return t == a1 or checktypelist(t,...)
      end
    end
    
    function mod:argcheck(val,argn,...)
      if not checktypelist(type(val),...) then
        local name = debugstack(2,1,0):match("in function `([^']+)'") or '?'
        local types = ('/'):join(tostringall(...))
        argn = tonumber(argn) or '?'
        error(err_fmt:format(argn,name,types,type(val)),3)
      end
    end
  end