lua-minser

Contents

• Functions

Modules

• minser

Topics

• README
• LICENSE

Module minser

Data serialization with minification.

This module contains functions to serialize values to strings, and deserialize these strings back to values. It is able to serialize strings, numbers, booleans, nil values, and tables.

Please note that not all tables can be serialized:

• For keys, only strings, numbers, and booleans are supported. For values, tables are supported in addition to the types for keys. An unsupported type will cause dump to return nil.
• Tables containing circular references will cause dump to return nil.
• Tables referenced more than once in the tree will be serialized separately each time, and will result in references to different tables.

If a table has a __minser metamethod, the method is called passing it the table itself and a table to cache seen sub-tables. The method should use the repr function for sub fields, passing it the "seen" table.

The serialized output is a chunk of Lua code yielding comparable values.

The module does its best to generate the most compact code possible.

Tables with consecutive numerical indices starting from 1 ("arrays") are efficiently stored by omitting the key. Numerical indices after the first nil element are output adorned.

local t = { 42, "Hello!", nil, "blah" }
print(dump(t)) --> {42,"Hello!",[4]="blah"}

Keys that are considered valid identifiers are output unadorned; other keys (including reserved words) are serialized as [key].

local t = { a=1, ["b"]=2, c=3 }
t["true"] = true
-- Note that this is just an example; the order of non-array
-- fields is random, so they may not appear as shown here.
print(serialize(t)) --> {a=1,b=2,c=3,["true"]=true}

A key is a valid identifier if and only if all the following are true:

• It is a string, and is not empty.
• It consists of only letters, digits, or the underscore. Note that since what Lua considers a "letter" or "digit" depends on the locale, we take a shortcut and only take into account ASCII letters and digits.
• It does not begin with a digit.
• It is not a reserved word as listed in the Lexical Conventions section of the manual for Lua 5.3.

The serialization algorithm only inserts a comma if needed, and it doesn't add any spaces. The serialized data does not contain the return statement, so this must be added if needed. The load function provided by this module takes care of adding it if needed.

Info:

• License: MIT. See LICENSE.md for details.
• Author: Diego Martínez https://github.com/kaeza

Functions

dump (...)	Serialize values.
repr (val, seen)	Serialize a single value.
load (data, env)	Load serialized data.

Functions

dump (...)

Serialize values.

Parameters:

• ... string, number, boolean or table Values to serialize.

Returns:

1. string Serialized data on success, nil on error.
2. optional string Error message.

repr (val, seen)

Serialize a single value.

Parameters:

• val string, number, boolean or table Value to serialize.
• seen optional table Cache of seen tables.

Returns:

1. string Serialized data on success, nil on error.
2. optional string Error message.

load (data, env)

Load serialized data.

Parameters:

• data string Serialized data.
• env table Environment for loaded chunk.

Returns:

1. number or nil Number of returned values on success, nil on error.
2. any or string First value on success, error message on error.
3. any Extra values are returned as extra results.