anal.lua - Pretty print any (sane) table

local serfuns = {
    table = function(tbl, recur)
        local result = {}
        local intkeys, maxint = 0, 0
        for k, v in pairs(tbl) do
            if intkeys and type(k) == "number" then
                if (k > 0) and (k % 1 == 0) then
                    intkeys = intkeys + 1
                    if k > maxint then
                        maxint = k
                    end
                end
            else
                intkeys = false
            end
            table.insert(result, "["..anal(k, recur).."]="..anal(v, recur))
        end
        if maxint == intkeys then
            result = {}
            for i,v in ipairs(tbl) do
                table.insert(result, anal(v))
            end
        end
        return ("{"..table.concat(result,", ").."}")
    end,
    string = function(x) return string.format("%q", x) end,
    ["function"] = tostring,
    boolean = tostring,
    userdata = tostring
}

_G.anal = function (thing, recur)
    recur = recur or {}
    local serfun = serfuns[type(thing)]
    if not serfun then
        return thing
    end
    if recur[thing] then
        return "*** REKURZE ***"
    end
    if type(thing) == "table" then
        recur[thing] = true
    end
    return serfun(thing, recur)
end