Semiconductor & Computer Engineering
Lua (pronounced LOO-ah[1]) is a light-weight, functional, garbage collected, dynamically-typed programming language designed to work as an extension or as an embedded scripting language. Lua is generally considered a very fast, very simple, and very small (program size) making it highly embeddable and portable. The official Lua implementation is portable and open-source, released under the MIT License. Lua only has one data structuring mechanism called tables.
History
Lua was created at PUC-Rio, the Pontifical Catholic University of Rio de Janeiro in Brazil in 1993 by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, and Waldemar Celes[2]. In 1993, Lua 1.0 was created as the first working implementation that worked. The implementation used yacc and lex using a stack-based virtual machine[3]. Much of the control structures syntax is borrowed from Modula.
The first public release of Lua was announced on Fri, 8 Jul 1994 in various usenet newsgroups. Lua sought internal exposure using various publications such as in the Dec 1996 issue Dr. Dobb's Journal.
luac
luac is Lua compiler that can translate Lua source code into binary files that can be later loaded and executed. This makes it possible for a program to not need to compile the source at run-time. This ability also allows for faster program loading but not necessarily smaller lua programs.[4]
Versions
| Version | Release Date | Description |
|---|---|---|
| 1.0 | 1993 | First working implementation |
| 1.1 | 1994 | Reference manual created, documentation established |
| 2.1 | 1995 | An value can be used as an index. Broke backwards compatibility Improved constructor semantics. |
| 2.4 | 1996 | The luac external compiler was created which compiled source code into bytecode and string tables packed in a portable binary format. This removed the need of programs to compile the source during run-time. |
| 3.1 | 1998 | Introduced closures and anonymous functions into the language. |
| 3.2 | 1999 | Multithreading support through no shared memory and multiple independent states. |
| 4.0 | 2000 | Added for loop, new set of API |
| 4.1 | 2001 | Coroutines added, portable implementation, deterministic semantics |
| 5.0 | 2003 | Register-based virtual machine. Tables were reimplemented. |
| 5.1 | 2006 | Incremental garbage collector was added. Better module support. |
| 5.2 | 2011 | Ephemeron tables implementation. Bitlib library added. Tables Finalizers |
Standard Libraries
- Main article: Lua Standard Libraries
Lua comes with a small set of standard libraries which can be used to perform frequent tasks. The libraries are mainly an interface to the underlining C API.