-- pairs_except(t, k) is the same as pairs(t), but with t[k] skipped
return function(t,exception)
	if exception == nil then return pairs(t) end
	local function next_except(t,k)
		local k2,v2 = next(t,k)
		if k2 == exception then k2,v2 = next(t,k2) end
		return k2,v2 end
	return next_except, t, nil end