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Crate oak_java

Crate oak_java 

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§🛠️ Java Parser Developer Guide

This guide is designed to help you quickly get started with developing and integrating oak-java.

§🚦 Quick Start

§Basic Parsing Example

The following is a standard workflow for parsing a Java class with modern features like Records and Annotations:

use oak_java::{JavaParser, SourceText, JavaLanguage};

fn main() {
    // 1. Prepare source code
    let code = r#"
        package com.example;
        
        import java.util.List;
        
        /**
         * Represents a user in the system.
         */
        @Entity
        public record User(String name, int age) {
            public void greet() {
                System.out.println("Hello, " + name);
            }
        }
    "#;
    let source = SourceText::new(code);

    // 2. Initialize parser
    let config = JavaLanguage::new();
    let parser = JavaParser::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 Java-specific constructs like class/record definitions, annotations, or complex method bodies.

§2. Incremental Parsing

No need to re-parse the entire source file when small changes occur:

// 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-java provides rich error contexts specifically tailored for Java developers, handling complex scenarios like missing semicolons or malformed annotations:

for diag in result.diagnostics() {
    println!("[{}:{}] {}", diag.line, diag.column, diag.message);
}

§🏗️ Architecture Overview

  • Lexer: Tokenizes Java source text into a stream of tokens, handling keywords, operators, literals, and support for Unicode identifiers.
  • Parser: Syntax analyzer based on the Pratt parsing algorithm to handle Java’s expression precedence, structural declarations, and modern language features.
  • AST: A strongly-typed syntax abstraction layer designed for high-performance Java analysis tools, IDEs, and refactoring engines.

§🔗 Advanced Resources

  • Full Examples: Check the examples/ folder in the project root.
  • API Documentation: Run cargo doc --open for detailed type definitions.
  • Test Cases: See tests/ for handling of various Java versions and edge cases. Java support for the Oak language framework.

Re-exports§

pub use crate::ast::JavaRoot;
pub use crate::builder::JavaBuilder;
pub use crate::language::JavaLanguage;
pub use crate::lexer::JavaLexer;
pub use crate::parser::JavaParser;
pub use crate::lsp::highlighter::JavaHighlighter;
pub use crate::lsp::JavaLanguageService;
pub use crate::mcp::serve_java_mcp;
pub use lexer::token_type::JavaTokenType;
pub use parser::element_type::JavaElementType;

Modules§

ast
AST module.
builder
Builder module.
language
Type definitions module. Language configuration module.
lexer
Lexer module.
lsp
LSP module.
mcp
MCP module.
parser
Parser module.