printtable.lua

local tinsert = table.insert
local tsort = table.sort

--- Recursively dumps a table's contents (sorted by the keys) to a file.
local function dumpTable(tbl, fname)
	local out = assert(io.open(fname, "w"))
	local visited = {}
	
	local function sortKey(a,b)
		local at, bt = type(a), type(b)
		if at ~= bt then
			return at < bt
		elseif at == "number" or at == "string" then
			return a < b
		else
			return tostring(a) < tostring(b)
		end
	end
	
	local function dumpTableHelper(t, level)
		
		local unvisited = {}
		
		-- Make list of keys
		local keys = {}
		for k,v in pairs(t) do
			if type(v) == "table" and not visited[v] then
				visited[v] = true
				unvisited[v] = true
			end
			
			tinsert(keys, k)
		end
		table.sort(keys, sortKey)
		
		-- Go through each key, now sorted.
		for _,k in ipairs(keys) do
			local v = t[k]
			
			for i=1,level do out:write("\t") end
			
			out:write(tostring(k), " = ", tostring(v))
			if type(v) == "table" and unvisited[v] then
				out:write(" {\n")
				dumpTableHelper(v, level+1)
				
				for i=1,level do out:write("\t") end
				out:write("}")
				
				unvisited[v] = nil
			end
			out:write(",\n")
		end
	end
	
	dumpTableHelper(tbl, 0)
	out:close()
end