Oak Java Parser

High-performance incremental Java parser for the oak ecosystem with flexible configuration, optimized for static analysis and code generation.

🎯 Overview

Oak Java is a robust parser for Java, designed to handle complete Java syntax including modern features. Built on the solid foundation of oak-core, it provides both high-level convenience and detailed AST generation for static analysis and code generation.

✨ Features

• Complete Java Syntax: Supports all Java features including modern specifications
• Full AST Generation: Generates comprehensive Abstract Syntax Trees
• Lexer Support: Built-in tokenization with proper span information
• Error Recovery: Graceful handling of syntax errors with detailed diagnostics

🚀 Quick Start

Basic example:

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_java::{JavaParser, JavaLanguage};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut session = ParseSession::<JavaLanguage>::default();
    let parser = JavaParser::new();
    let source = SourceText::new(r#"
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}
    "#);
    
    let result = parser.parse(&[], &mut session);
    println!("Parsed Java successfully.");
    Ok(())
}

📋 Parsing Examples

Method Parsing

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_java::{JavaParser, JavaLanguage};

let mut session = ParseSession::<JavaLanguage>::default();
let parser = JavaParser::new();
let source = SourceText::new(r#"
public class Calculator {
    public int add(int a, int b) {
        return a + b;
    }
    
    public static void main(String[] args) {
        Calculator calc = new Calculator();
        int result = calc.add(5, 3);
        System.out.println("Result: " + result);
    }
}
"#);

let result = parser.parse(&[], &mut session);
println!("Method parsed successfully.");

Class Parsing

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_java::{JavaParser, JavaLanguage};

let mut session = ParseSession::<JavaLanguage>::default();
let parser = JavaParser::new();
let source = SourceText::new(r#"
public class Person {
    private String name;
    private int age;
    
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    
    public String getName() {
        return name;
    }
    
    public int getAge() {
        return age;
    }
}
"#);

let result = parser.parse(&[], &mut session);
println!("Class parsed successfully.");

🔧 Advanced Features

Token-Level Parsing

use oak_core::{Parser, SourceText, parser::session::ParseSession};
use oak_java::{JavaParser, JavaLanguage};

let mut session = ParseSession::<JavaLanguage>::default();
let parser = JavaParser::new();
let source = SourceText::new("int x = 42;");
let result = parser.parse(&[], &mut session);

println!("Token parsing completed.");

### Error Handling
```rust
use oak_java::{Parser, JavaLanguage, SourceText};

let parser = Parser::new();
let source = SourceText::new(r#"
// Invalid Java code example
public class BrokenClass {
    public static void main(String[] args {
        System.out.println("Hello")
    // Missing closing braces
}
"#);

let result = parser.parse(&source);
if let Some(errors) = result.result.err() {
    println!("Parse errors found: {:?}", errors);
} else {
    println!("Parsed successfully.");
}

🏗️ AST Structure

The parser generates a comprehensive AST with the following main structures:

• JavaProgram: Root container for Java programs
• Class: Java class definitions
• Method: Java methods and constructors
• Statement: Various statement types including control flow
• Expression: Various expression types including operators
• Type: Java type system constructs

📊 Performance

• Streaming: Parse large Java files without loading entirely into memory
• Incremental: Re-parse only changed sections
• Memory Efficient: Smart AST node allocation
• Fast Recovery: Quick error recovery for better IDE integration

🔗 Integration

Oak Java integrates seamlessly with:

• Static Analysis: Code quality and security analysis
• Code Generation: Generating code from Java AST
• IDE Support: Language server protocol compatibility
• Refactoring: Automated code refactoring
• Documentation: Generating documentation from Java code

📚 Examples

Check out the examples directory for comprehensive examples:

• Complete Java program parsing
• Method and class analysis
• Code transformation
• Integration with development workflows

🤝 Contributing

Contributions are welcome!

Please feel free to submit pull requests at the project repository or open issues.