Module reader 

LuacReader Module

This module is responsible for reading and parsing .luac files (Lua bytecode files).

Main Responsibilities

1. Header Parsing: Read and verify header data such as magic numbers and version information of .luac files.
2. Bytecode Deserialization: Convert binary bytecode into the internal LuaProgram structure.
3. Lazy Loading: Use OnceLock to implement delayed parsing for improved performance.
4. Error Handling: Provide detailed error information and diagnostics.

Usage Example

use lua_assembler::formats::luac::{LuacReadConfig, reader::LuacReader};
use std::fs::File;

// Create configuration
let config = LuacReadConfig::default();

// Open file and create reader
let file = File::open("example.luac")?;
let reader = config.as_reader(file);

// Get file info
let info = reader.get_info()?;
println!("Lua version: {:?}", info.version);

// Parse full program
let result = reader.finish();

Design Principles

• Lazy Loading: Parse file content only when needed.
• Error Propagation: Use Result types to ensure errors are correctly propagated.
• Memory Efficiency: Avoid repeated parsing by using OnceLock to cache results.
• Type Safety: Use strong typing to ensure data correctness.

Module Structure

• LuacReader<'config, R>: Main reader structure.
• LuacInfo: Lightweight structure containing file header info.
• read_header(): Parses the .luac file header.
• read_code_object(): Parses bytecode objects (currently a placeholder implementation).

Lua Bytecode Format

Basic structure of a .luac file:

1. Magic number: \x1bLua (4 bytes)
2. Version info (1 byte)
3. Format version (1 byte)
4. Endianness flag (1 byte)
5. Various size information (multiple bytes)
6. Bytecode data

Maintenance Notes

• The current read_code_object method returns default values and needs a full bytecode parsing implementation for specific Lua versions.
• Supporting multiple Lua versions requires adding version-specific logic in read_header.
• Error handling should provide enough context information for debugging.

Structs

LuacInfo

LuacInfo 表示 .luac 文件的基本信息视图

LuacReader

现代化的惰性 .luac 文件读取器