Coco

Status: Early implementation — syntax, type checker, bytecode VM runtime, concurrency primitives, and stdlib/IO modules are functional.

Current execution model: Bytecode VM only. coco run type-checks and executes source via the VM path. coco build emits a .cb artifact via coco_interpreter::serialize_chunk; coco build --disasm prints bytecode disassembly. The old AOT/LLVM backend and coco build --binary are not present.

What is Coco?

Coco is a memory-safe, gradually typed language for backend services, CLI tools, and automation. It targets JS/TS/PHP developers who want memory safety without Rust's learning curve.

Quick start

cargo build
cargo run -- hello.co
cargo test

Project structure

• crates/coco_cli: CLI binary
• crates/coco_parser: parser
• crates/coco_typeck: gradual type checker
• crates/coco_interpreter: bytecode compiler, stack VM, .cb serialization
• crates/coco_formatter: formatter
• crates/coco_syntax: AST definitions
• tests/: .co integration tests

Install

Linux

bash scripts/package-linux.sh
sudo dpkg -i dist/linux-amd64/coco_*.deb

macOS

bash scripts/package-macos.sh
sudo installer -pkg dist/macos-<arch>/coco-<version>-<arch>.pkg -target /

Windows

powershell -ExecutionPolicy Bypass -File .\scripts\package-windows.ps1

Extract dist\windows-amd64\coco-<version>-windows-amd64.zip and place coco.exe on your PATH.

Direct binary install

cargo build --release
sudo install -m 0755 target/release/coco /usr/local/bin/coco

Build

cargo build

Run

cargo run -- hello.co

Test

cargo test

Single crate tests:

cargo test -p coco_interpreter
cargo test -p coco_typeck

CLI reference

Command	Notes
coco lex FILE.co	Tokenize
coco parse FILE.co	Print AST
coco fmt FILE.co	Format
coco fmt -w FILE.co	Format in-place
coco check FILE.co	Parse + diagnostics
coco typecheck FILE.co	Type checking
coco safety FILE.co	Safety analysis
coco run FILE.co	Type-check + VM execute
coco run --no-check FILE.co	VM execute without checks
cargo run -- build FILE.co	Serialize .cb
cargo run -- build --disasm FILE.co	Bytecode disassembly

Design goals

• Memory safety by default
• Optional gradual typing
• Safe concurrency primitives
• Practical bytecode VM performance
• Explicit future compatibility; no backward-compat hacks

Roadmap

Near-term:

• Finalize safe error-runtime behavior on VM paths
• Complete project graph resolution for multi-file builds
• Stabilize stdlib/host integration
• Add APC advisory coverage where apc-advisory is enabled

Deferred:

• Runtime package management surface
• Self-hosting compiler
• JIT/WASM output
• AOT/native-backend research is explicit, tracked, and not currently enabled

Contributing

See CONTRIBUTING.md.