Lua table.toString(tableName) and table.fromString(stringTable) functions?

Dustin Gamester picture Dustin Gamester · May 20, 2011 · Viewed 41.5k times · Source

I am wanting to convert a 2d lua table into a string, then after converting it to a string convert it back into a table using that newly created string. It seems as if this process is called serialization, and is discussed in the below url, yet I am having a difficult time understanding the code and was hoping someone here had a simple table.toString and table.fromString function
http://lua-users.org/wiki/TableSerialization

Answer

Henrik Ilgen picture Henrik Ilgen · May 21, 2011

I am using the following code in order to serialize tables:

function serializeTable(val, name, skipnewlines, depth)
    skipnewlines = skipnewlines or false
    depth = depth or 0

    local tmp = string.rep(" ", depth)

    if name then tmp = tmp .. name .. " = " end

    if type(val) == "table" then
        tmp = tmp .. "{" .. (not skipnewlines and "\n" or "")

        for k, v in pairs(val) do
            tmp =  tmp .. serializeTable(v, k, skipnewlines, depth + 1) .. "," .. (not skipnewlines and "\n" or "")
        end

        tmp = tmp .. string.rep(" ", depth) .. "}"
    elseif type(val) == "number" then
        tmp = tmp .. tostring(val)
    elseif type(val) == "string" then
        tmp = tmp .. string.format("%q", val)
    elseif type(val) == "boolean" then
        tmp = tmp .. (val and "true" or "false")
    else
        tmp = tmp .. "\"[inserializeable datatype:" .. type(val) .. "]\""
    end

    return tmp
end

the code created can then be executed using loadstring(): http://www.lua.org/manual/5.1/manual.html#pdf-loadstring if you have passed an argument to 'name' parameter (or append it afterwards):

s = serializeTable({a = "foo", b = {c = 123, d = "foo"}})
print(s)
a = loadstring(s)()