# 🛠️ YAML Parser Developer Guide
Yaml support for the Oak language framework.
This guide is designed to help you quickly get started with developing and integrating `oak-yaml`.
## 🚦 Quick Start
Add the dependency to your `Cargo.toml`:
```toml
[dependencies]
oak-yaml = { path = "..." }
```
### Basic Parsing Example
The following is a standard workflow for parsing a YAML document:
```rust
use oak_yaml::{YamlParser, SourceText, YamlLanguage};
fn main() {
// 1. Prepare source code
let code = r#"
version: "3.8"
services:
web:
image: "nginx:latest"
ports:
- "80:80"
db:
image: "postgres:13"
environment:
POSTGRES_PASSWORD: example
"#;
let source = SourceText::new(code);
// 2. Initialize parser
let config = YamlLanguage::new();
let parser = YamlParser::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.");
}
}
```
## 🔍 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 YAML mappings, sequences, scalars, and handle anchors/aliases.
### 2. Incremental Parsing
No need to re-parse massive YAML configuration files when small changes occur:
```rust
// Assuming you have an old parse result 'old_result' and new source text 'new_source'
let new_result = parser.reparse(&new_source, &old_result);
```
### 3. Diagnostics
`oak-yaml` provides precise error feedback for malformed YAML, such as indentation errors, unmatched brackets, or invalid tag usage:
```rust
for diag in result.diagnostics() {
println!("[{}:{}] {}", diag.line, diag.column, diag.message);
}
```
## 🏗️ Architecture Overview
- **Lexer**: Tokenizes YAML source text into a stream of tokens, handling indentation, block vs. flow styles, and various scalar formats.
- **Parser**: Syntax analyzer based on the Pratt parsing algorithm to handle YAML's hierarchical structure and complex value types.
- **AST**: A strongly-typed syntax abstraction layer designed for high-performance YAML analysis, formatting, and validation 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/](tests/) for handling of various YAML features and edge cases.