# 🛠️ TeX/LaTeX Parser Developer Guide
TeX support for the Oak language framework.
This crate provides lexing, parsing, and AST building for TeX/LaTeX documents,
enabling integration with the Oak language server and other tools.
This guide is designed to help you quickly get started with developing and integrating `oak-tex`.
## 🚦 Quick Start
Add the dependency to your `Cargo.toml`:
```toml
[dependencies]
oak-tex = { path = "..." }
```
### Basic Parsing Example
The following is a standard workflow for parsing TeX/LaTeX documents, supporting commands, environments, and math mode:
```rust
use oak_tex::{TexParser, SourceText, TexLanguage};
fn main() {
// 1. Prepare source code
let code = r#"
\documentclass{article}
\begin{document}
The value of $\pi$ is approximately 3.14159.
\end{document}
"#;
let source = SourceText::new(code);
// 2. Initialize parser
let config = TexLanguage::new();
let parser = TexParser::new(&config);
// 3. Execute parsing
let result = parser.parse(&source);
// 4. Handle results
if result.is_success() {
println!("Parsing successful! AST node count: {}", result.node_count());
} else {
eprintln!("Errors found during parsing.");
for diag in result.diagnostics() {
println!("[{}:{}] {}", diag.line, diag.column, diag.message);
}
}
}
```
## 🔍 Core API Usage
### 1. Syntax Tree Traversal
After a successful parse, you can use the built-in visitor pattern or manually traverse the Green/Red Tree to extract TeX specific constructs like commands, environments, math mode groups, and plain text content.
### 2. Incremental Parsing
TeX documents can be very large (e.g., theses, books). `oak-tex` supports sub-millisecond incremental updates:
```rust
// Re-parse only the modified section
let new_result = parser.reparse(&new_source, &old_result);
```
### 3. Error Recovery
The parser is designed for industrial-grade fault tolerance, recovering gracefully from unclosed environments or missing braces to provide continuous feedback in IDEs.
## 🏗️ Architecture Overview
- **Lexer**: Tokenizes TeX source text, supporting control sequences, category codes (catcodes), and special characters.
- **Parser**: A high-performance recursive descent parser that handles TeX's macro-based expansion and environment nesting.
- **AST**: A strongly-typed, lossless syntax tree that preserves all trivia (comments/whitespace) for refactoring and formatting tools.
## 🔗 Advanced Resources
- **Full Examples**: Check the [examples/](examples/) folder in the project root.
- **API Documentation**: Run `cargo doc --open` for detailed type definitions.
- **Test Cases**: See [tests/readme.md](tests/readme.md) for details on our snapshot-based testing.