--
-- $Header: /Users/dap/lua/RCS/dump.lua,v 1.4 2007/02/11 08:32:44 dap Exp $
--
-- dump - dump out information about an object
--

local string_meta = getmetatable(' ')
local func_env    = getfenv(getfenv)
local dump_done    = { fenv = {} }

local function indented(lvl, out, fmt, ...)
   fmt = (" "):rep(2*lvl) .. fmt

   out(fmt, unpack(arg))
end

local function varname(v, name)
   if not name then
      if type(v) == 'table' and v.__name and type(v.__name) == 'string' then
	 name = v.__name
      else
	 name = '**gok'
      end
   end
   return tostring(name)
end

local function dump_str(v, name, out, lvl)
   indented(lvl, out, "%8s = '%s'", varname(v, name), v)
end

local function dump_fun(v, name, out, lvl)
   indented(lvl, out, "%8s = %s", varname(v, name), tostring(v))
end

local function dump_num(v, name, out, lvl)
   indented(lvl, out, "%8s = %s", varname(v, name), tostring(v))
end

local function dump_userdata(v, name, out, lvl)
   indented(lvl, out, "%8s = '%s'", varname(v, v), tostring(v))
end

local function dump_boolean(v, name, out, lvl)
   indented(lvl, out, "%8s = %s", varname(v, v), tostring(v))
end

local function dump_nil(v, name, out, lvl)
   indented(lvl, out, "%8s = nil", varname(v, name))
end

local function dump_tab(tab, name, out, lvl, seen)
   name = varname(tab, name)
   seen[tab] = true

   indented(lvl, out, '%8s = { %s', name, tostring(tab))

   for k, v in pairs(tab) do
      if v == tab then
	 -- self referential
	 indented(lvl+1, out, '%8s = <*self*>', k)
      else
	 dump(v, k, out, lvl+1, seen)
      end
   end
   indented(lvl, out, '}')
end

local function dump_mt(v, name, out, lvl, seen)
   local mt = getmetatable(v)

   if mt then
      dump(mt, ("meta '%s'"):format(varname(v, name)) , out, lvl, seen)
   end
end

function dump(v, name, out, lvl, seen)
   local t = type(v)
   local o = out or function (fmt, ...) print(fmt:format(unpack(arg))) end
   local lvl = lvl or 0

   if not seen then
      seen = dump_done;
      seen.fenv[func_env] = true -- only show unusual ones
   end

   if t == 'table' then
      if seen and not seen[v] then
	 dump_tab(v, name, o, lvl, seen)
      else
	 local tnam = ''
	 if v.__name and type(v.__name) == 'string' then
	    tnam = ' (' .. v.__name .. ')'
	 end

	 indented(lvl, o, '%8s = %s%s', varname(v, name), tostring(v), tnam)
      end
   elseif t == 'function' then
      dump_fun(v, name, o, lvl)
   elseif t == type('string') then
      dump_str(v, name, o, lvl)
   elseif t == type(1) then
      dump_num(v, name, o, lvl)
   elseif t == type(true) then
      dump_boolean(v, name, o, lvl)
   elseif t == 'userdata' then
      dump_num(v, name, o, lvl)
   elseif t == type(nil) then
      dump_nil(v, name, o, lvl)
   else
      indented(lvl, o, '%8s = ***** type %s %s', name, t, tostring(v))
   end

   local mt = getmetatable(v)
   if mt and t ~= 'string' or mt ~= string_meta then
      dump_mt(v, name, o, lvl, seen)
   end

   local fenv = debug.getfenv(v)
   if fenv and not seen.fenv[fenv] then
      seen.fenv[fenv] = true
      dump(fenv, 'fenv for ' .. name, o, lvl+1, seen)
   end
end

-- mark the global table as seen
--   dump(_G, nil, function () end)
-- faster:

dump_done[_G] = true

return true