Lua Docs

Lua

Lua is a powerful, efficient, lightweight, embeddable scripting language. It supports procedural programming, object-oriented programming, functional programming, data-driven programming, and data description. Lua combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. It is dynamically typed, runs by interpreting bytecode with a register-based virtual machine, and has automatic memory management with generational garbage collection.

Specification: Lua 5.5 Reference Manual

---

Quick Reference

| Topic | File | |------|------| | Introduction (what is Lua, design, embedding, extension language) | introduction.md | | Values & Types (nil, boolean, number, string, function, userdata, thread, table; metatables; metamethods; GC; weak tables) | types.md | | Syntax (lexical conventions, identifiers, keywords, strings, comments, variables, scoping) | syntax.md | | Statements & Expressions (blocks, chunks, assignment, control structures, for loops, operators, precedence, table constructors, function definitions, multiple results) | expressions.md | | Coroutines (create, resume, yield, wrap, states, collaborative multithreading) | coroutines.md | | Standard Libraries (basic, string, table, math, I/O, OS, UTF-8, debug, modules) | standard-libraries.md | | Patterns (character classes, pattern items, captures, balanced match, frontier) | patterns.md | | C API (stack, registry, C closures, error handling, status codes, yields, debug interface, auxiliary library) | c-api.md | | Standalone Interpreter (CLI options, arg table, environment variables, interactive mode) | standalone.md | | Migration & Syntax (incompatibilities with 5.4, complete syntax grammar) | migration.md |

---

Core Concepts

• Values and Types: Eight basic types — nil, boolean, number, string, function, userdata, thread, table. All values are first-class.
• Tables: The sole data-structuring mechanism — arrays, lists, sets, records, graphs, trees. Associative arrays with any key type (except nil and NaN).
• Metatables & Metamethods: Extensible semantics — operator overloading, indexing control, calls, GC finalizers, tostring, pairs, length.
• Coroutines: Collaborative multithreading — coroutine.create, resume, yield, wrap, close.
• Closures: Functions capture upvalues (external local variables) from their lexical scope.
• Garbage Collection: Incremental and generational modes, GC metamethods (__gc), weak tables (__mode).
• C API: Stack-based interaction — push/pop values, registry, C closures, error handling, continuation functions.
• Patterns: Lightweight pattern matching (not full regex) — character classes, captures, balanced match, frontier patterns.
• Modules: require, package.path, package.cpath, searchers, preload.
• _ENV: Every chunk compiled in scope of _ENV; global variables are _ENV.var.

---

Official Documentation

• Lua 5.5 Reference Manual
• Lua Documentation
• Programming in Lua (4th edition)
• Lua Users Wiki
• Lua FAQ
• Lua License

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: pledgeandgrow
• Source: pledgeandgrow/pledge-skills
• License: MIT

Install and usage instructions live in the source repository linked above.