CantaLoop

A functional programming language implementation in Rust with a complete toolchain including parser, type checker, bytecode compiler, virtual machine, and Language Server Protocol support.

Features

• Parser using Pest with Pratt parser for operator precedence
• Semantic analysis and type checking with HIR (High-level Intermediate Representation) lowering
• Bytecode compilation with optimization passes
• Stack-based virtual machine with NaN-boxed values for efficient execution
• Language Server Protocol (LSP) support for IDE integration
• Project management tool (melon) for creating and running projects
• Module system with dot-path imports
• Lazy evaluation with thunks and function composition
• Standard library with math, string, array, and functional utilities

Quick Start

Using the Melon Tool (Recommended)

The melon tool provides project management and execution:

# Create a new project
cargo run --bin melon -- new myproject
cd myproject

# Run the project
cargo run --bin melon -- run

# Run with watch mode (auto-rebuild on file changes)
cargo run --bin melon -- run --watch

# Run with debug output (AST, HIR, bytecode)
cargo run --bin melon -- run --debug

Running Individual Files

# Build the interpreter
cargo build --release

# Run a single file
cargo run --bin melon -- run examples/language_features/helloworld.mln

LSP Setup

The LSP provides real-time diagnostics, hover information, code completion, and semantic tokens. See BUILD.md for building and installing the VS Code/Cursor extension.

Building

# Build all binaries
cargo build --release

# Build specific binaries
cargo build --release --bin melon          # Project manager
cargo build --release --bin cantaloop-lsp  # LSP server

Project Structure

• src/core/ - Core language implementation
  • parser.rs - Pest-based parser
  • ast/ - Abstract Syntax Tree (enums, builder)
  • hir_lowering/ - Type checking and HIR generation
  • bytecode/ - Bytecode compilation (emitter, opcode)
  • vm.rs - Stack-based virtual machine
  • engine.rs - Compilation and execution orchestration
  • projectLoader.rs - Project loading and module resolution
• src/lsp/ - Language Server Protocol implementation
• src/melon/ - Project management CLI tool
• src/stdlib/ - Standard library modules
• examples/ - Example .mln files and projects
• documentation/ - Architecture and design documentation

See documentation/ARCHITECTURE.md for a detailed description of the system architecture.