Crate oak_j 

🛠️ 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:

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:

use oak_j::{JParser, JLanguage};
use oak_core::{SourceText, Parser, parser::ParseSession};

// Assume we already have a parser instance
// Assume you have the old parse result and new source code
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:

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/ folder in the project root.
• API Documentation: Run cargo doc --open for detailed type definitions.
• Test Cases: See tests/ for handling of various J edge cases and language versions.

Re-exports

pub use language::JLanguage;

pub use lexer::JLexer;

pub use lexer::JTokenType;

pub use parser::JElementType;

pub use parser::JParser;

pub use crate::lsp::highlighter::JHighlighter;

pub use crate::lsp::JLanguageService;

pub use crate::lsp::formatter::JFormatter;

pub use crate::mcp::serve_j_mcp;

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.

Traits

ElementType

A trait for types that represent an element’s kind in a syntax tree.

Language

Language definition trait that coordinates all language-related types and behaviors.

TokenType

A trait for types that represent a token’s kind in a specific language.