Inspecting argument names

[Daurnimator <quae@...>]

I'm trying to find a way to get the argument names via the debug
interface, but falling flat on my face.
==> they aren't available from debug.getinfo

The best idea I've got at the moment is to set a call hook and then
inspect with debug.getlocal; but I can't bail out of the function from
a hook:

       local names
       local function hook ()
               debug.sethook() --Turn off hook.
               names = {}
               local i=1
               while true do
                       local name , value = debug.getlocal(2,i)
                       if name == nil or name:sub(1,1) == "(" then break end
                       names[i]=name
                       i=i+1
                       --print(name,value)
               end
       end
       local function getargnames ( func )
               debug.sethook(hook,"c")
               func()
               return names
       end
       local argnames = getargnames(function(a,b,c) print("Don't do the
function") end)

If I try to throw an error from the hook; I can't seem to catch it
with a pcall. Also pcall seems to make the argument list disappear.
(replace func() above with pcall(func))

Anyone got any ideas?
Failing any good ideas; could the lua authors include this in the
debug info somewhere?

Regards,
Daurn.