# 🛠️ J Parser Developer Guide
J support for the Oak language framework.
This guide is designed to help you quickly get started with developing and integrating `oak-j`.
## 🚀 Quick Start
### Basic Parsing Example
The following is a standard workflow for parsing J source code:
```rust
use oak_j::{JParser, JLanguage};
use oak_core::{SourceText, Parser, parser::ParseSession};
fn main() {
// 1. Prepare source code
let code = "a =: 1 + 2";
let source = SourceText::new(code);
// 2. Initialize parser
let config = JLanguage::default();
let parser = JParser::new(&config);
// 3. Execute parsing
let mut session = ParseSession::new(1024);
let result = parser.parse(&source, &[], &mut session);
// 4. Handle result
if result.result.is_ok() {
println!("Parsed successfully!");
}
}
```
## 🔍 Core API Usage
### 1. Syntax Tree Traversal
After successful parsing, you can use the built-in visitor pattern or manually traverse the Green/Red Tree.
### 2. Incremental Parsing
When the source code changes slightly, there's no need to re-parse the entire document:
```rust
use oak_j::{JParser, JLanguage};
use oak_core::{SourceText, Parser, parser::ParseSession};
// Assume we already have a parser instance
# let config = JLanguage::default();
# let parser = JParser::new(&config);
// Assume you have the old parse result and new source code
# let new_source = SourceText::new("a =: 2");
let mut session = ParseSession::new(1024);
// In a real scenario, the session will keep the old tree for incremental comparison
let new_result = parser.parse(&new_source, &[], &mut session);
```
### 3. Diagnostics
`oak-j` provides rich error context:
```rust
# use oak_j::{JParser, JLanguage};
# use oak_core::{SourceText, Parser, parser::ParseSession};
# let config = JLanguage::default();
# let parser = JParser::new(&config);
# let source = SourceText::new("a =:");
# let mut session = ParseSession::new(1024);
# let result = parser.parse(&source, &[], &mut session);
for diag in result.diagnostics {
println!("{:?}", diag);
}
```
## 🏗️ Architecture Overview
- **Lexer**: Tokenizes J source text into a stream of tokens, handling keywords (case-insensitive), operators, and numeric literals.
- **Parser**: Syntax analyzer based on the Pratt parsing algorithm to handle J's structural declarations and expression precedence.
- **AST**: A strongly-typed syntax abstraction layer designed for building high-performance J analysis tools and IDEs.
## 📚 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 J edge cases and language versions.