Lua prettyprinter

gistfile1.lua

#!/usr/bin/env lua

-- works like PHP's print_r(), returning the output instead of printing it to STDOUT

function prettyprint(data)
	-- cache of tables already printed, to avoid infinite recursive loops
	local tablecache = {}
	local buffer = ""
	local padder = "    "
	local inited = 0

	local function _prettyprint(d, depth)
		local t = type(d)
		local str = tostring(d)
		local items = 0

		if (t == "table") then
			if (tablecache[str]) then
				-- table already dumped before, so we dont
				-- dump it again, just mention it
				buffer = buffer.."<"..str..">"
			else
				tablecache[str] = (tablecache[str] or 0) + 1
				items = 0
				for k, v in pairs(d) do items = items + 1 end
				buffer = buffer.."("..str.." n="..items..") {"
				items = 0
				for k, v in pairs(d) do
					if (items == 0) then
						buffer = buffer .. "\n"
					end
					items = items + 1
					if (type(k) == "string") then
						k = '"' .. k .. '"'
					end
					buffer = buffer..string.rep(padder, depth+1).."["..k.."] => "
					_prettyprint(v, depth+1)
				end
				if (items > 0) then
					buffer = buffer..string.rep(padder, depth).."}"
				else
					buffer = buffer.."}"
				end
			end
		elseif (t == "number") then
			buffer = buffer.."("..t..") "..str..""
		else
			buffer = buffer.."("..t..") \""..str.."\""
		end
		if (depth > 0) then
			buffer = buffer .. "\n"
		end
	end
	_prettyprint(data, 0)
	return buffer
end

--[[
print(prettyprint({
	[1] = "this is the first element",
	[2] = "and this is the second",
	[3] = 3,
	[4] = 3.1415,
	["nested"] = {
		["lua"] = "is cool but",
		["luajit"] = "is fucking awesome!",
		["even_for"] = {"almost", "empty", {}},
	},
	["some-files"] = {
		[0] = io.stdin,
		[1] = io.stdout,
		[2] = io.stderr
	}
}))

-- outputs:

(table: 0x40e16320 n=6) {
    [1] => (string) "this is the first element"
    [2] => (string) "and this is the second"
    [3] => (number) 3
    [4] => (number) 3.1415
    ["nested"] => (table: 0x40e16370 n=3) {
        ["lua"] => (string) "is cool but"
        ["luajit"] => (string) "is fucking awesome!"
        ["even_for"] => (table: 0x40e163d0 n=3) {
            [1] => (string) "almost"
            [2] => (string) "empty"
            [3] => (table: 0x40e16410 n=0) {}
        }
    }
    ["some-files"] => (table: 0x40e0f010 n=3) {
        [0] => (userdata) "file (0x3f1e79b6a0)"
        [1] => (userdata) "file (0x3f1e79b780)"
        [2] => (userdata) "file (0x3f1e79b860)"
    }
}

]]

Thanks for this version!