Luaチュートリアル(VIII)。データの永続化

    Entry { "Stephen Liu", "Male", "Programmer", "BS" }
    Entry { "Jerry Tian", "Male", "Programmer", "BS" }

local count = 0
-- The Entry function is pre-defined here so that when the data code in the dofile is executed, it can find a match for that function.
function Entry() count = count + 1 end
dofile("d:/lua_data.conf")
print("number of entries: " . count)

-- The output is.
--number of entries: 2

    Entry { name = "Stephen Liu", gender = "Male", job = "Programmer", education = "BS" }
    Entry { name = "Jerry Tian", gender = "Male", job = "Programmer", education = "BS" }

local personInfo = {}
function Entry(b)
    -- Here the name field value of table object b is used as the key information of personInfo.
    if b.name then
        personInfo[b.name] = true
    end
end

dofile("d:/lua_data.conf")
for name in pairs(personInfo) do
    print(name)
end

-- The output is.
--Jerry Tian
--Stephen Liu

 function serialize(o)
    if type(o) == "number" then
        io.write(o)
    elseif type(o) == "string" then
        The "%q" parameter of the --string.format function escapes the metacharacters in the string.
        io.write(string.format("%q",o))
    elseif type(o) == "table" then
        io.write("{\n")
        -- Iterate over the elements of the table while recursively writing the value of each field.
        -- As you can see, this simple example can support nested tables.
        for k,v in pairs(o) do
            -- This is done to prevent k from containing illegal Lua identifiers.
            io.write(" ["); serialize(k); io.write("] = ")
            serialize(v)
            io.write(",\n")
        end
        io.write("}\n")
    else
        error("can't serialize a " . type(o))
    end
end