printr.lua

-- this goes in your LUA_PATH, which is usually:
-- /usr/share/lua/5.1/
-- /usr/local/share/lua/5.1
-- C:\Program Files\Lua\5.1
-- first, require("printr")
-- then, use the function printr()
-- this code is public domain

local stringFormat,stringRep,stringChar = string.format,string.rep,string.char
local tableInsert,tableConcat = table.insert,table.concat

local function serializevalue(v, d, n)
    local d = d or {}
    local t = type(v)
    if t == "string" then
        v:gsub("\\\n", "\\n"):gsub("\r", "\\r"):gsub(stringChar(26), "\"..string.char(26)..\"")
        return stringFormat("%q", v)
    elseif t == "number" then
        return stringFormat("%d", v)
    elseif t == "boolean" then
        return stringFormat("%s", tostring(v))
    elseif t == "table" then
        if d[v] then
            return "{...}"
        end
        d[v] = true
        return stringFormat("%s", serializetable(v, d, n+1))
    else
        return '"'..tostring(v)..'"'
    end
end
function serializetable(table, d, n)
    local s,n = {},n or 1
    tableInsert(s, "{\n")
    for k,v in pairs(table) do
        tableInsert(s, stringRep("\t", n))
        tableInsert(s, serializevalue(k, d, n).." = ")
        tableInsert(s, serializevalue(v, d, n))
        tableInsert(s, ",\n")
    end
    if s[#s] == ",\n" then
        s[#s] = "\n"
    end
    tableInsert(s, stringRep("\t", n-1))
    tableInsert(s, "}")
    return tableConcat(s)
end

function printr(t)
    return print(serializetable(t))
end