json2lua

This program converts JSON to Lua efficiently. Instead of parsing and loading the entire JSON data at once, which would cost quite some memory, it reads and processes the input in chunks.

Currently, the project comprises two components:

• libenc, a small C++ library implementing encoding and decoding of text.
• libjson2lua, a C++ library implementing a flexible, pull-style JSON-to-Lua parser and converter. It is kept in tree because it is developed for the program.
• json2lua, the C++ program which exposes the required functionality to the command line.

In the future, the program might be expanded to support more encodings and, perhaps, to write bytecode directly.

Build

The Tup build system manages the process, which comprises three steps: configuration, build and testing.

Configuration

Parameters are specified in the usual way, in a tup.config file. You might be interested in using variants.

The steps are as follows:

1. Choose an appropriate toolchain (CONFIG_TOOLCHAIN). Toolchains are defined in src/toolchains.tup.
2. Fulfill the config items required or supported by the chosen toolchain (e.g. CONFIG_CXXFLAGS for the GNU toolchain).
3. Choose appropriate values for toolchain-independent variables (like CONFIG_BUFFER_SIZE).

The provided tup.config contains the explanation of toolchain-independent variables.

Example configurations which may or may not be suitable for your build environment are provided in configs.tup. You could try to proceed to the build step by using one of them after adding your settings for the toolchain-independent parameters.

Build

The build step follows the standard procedure:

$  tup

Requirements

• the Tup build system
• a C++ toolchain
• guardcheader
• the standard Lua interpreter

Testing

Tests are part of the build as well, and thus managed by Tup.

Tests have been implemented for the command-line program. As they involve a compiled executable, they can be carried out only if the target architecture for which the program was built matches that on which it was built. They will be run automatically if that's the case, and, if any of them fails, Tup will complain.

Usage

The accepted command-line depends on the version.

All versions admit the GNU standard to find it out:

$  json2lua --version

This prints json2lua something VERSION, where VERSION is the last token and represents the version.

Current version

The current version handles UTF-8-encoded JSON and outputs ASCII-encoded Lua 5.

The program shall be invoked as follows:

$  json2lua INPUT OUTPUT

INPUT and OUTPUT are the names of the files that shall be read and written, respectively.