RizzoMemory

MSc thesis project implementing Rizzo, a programming language based on the work of Rizzo by Patrick Bahr, with a focus on memory management and safety. The project includes:

• A compiler that translates Rizzo source code to C, leveraging reference counting for memory management.
• A C runtime library that provides memory management primitives, safety checks and the Rizzo advance and update semantics.
• A VS Code extension that integrates the Rizzo compiler and language server for an enhanced development experience with diagnostics, hover information, and code navigation (Rough implementation; not the focus of the MSc thesis).

Prerequisites

• OCaml (4.14+) and opam — for building the compiler
• Dune — OCaml build system (usually installed via opam)
• GCC or Clang — for compiling generated C code
• Node.js and npm — for the VS Code extension (optional)

Development

• Build: opam exec -- dune build
• Run compiler on one or more source files: opam exec -- dune exec rizzoc ./examples/first.rizz

By default the compiler is quiet and only emits output.c. To inspect the intermediate ASTs while compiling, pass --print-ast to rizzoc.

Full flow: compile and run a .rizz file

The full pipeline compiles one or more Rizzo source files to C and then runs them:

# 1. Compile .rizz → output.c
opam exec -- dune exec rizzoc <file.rizz> [more-files.rizz ...]

# 2. Compile output.c with the C runtime headers
gcc -I./src/runtime output.c -o output

# 3. Run
./output

Or use the convenience npm script from the repo root (after step 1):

npm run rizzo

Windows: The extension automatically handles Windows-specific details (.exe extension, -m64 flag). Both GCC and Clang are supported.

Implicit stdlib

File-based compilation and editor analysis now prepend a compiler-owned stdlib before user files are typechecked. The default stdlib lives in src/stdlib in the repository and installs next to the compiler under lib/rizzoc/stdlib. That means user .rizz files can use combinators such as map, zip, scan, and filter_map without copy-pasting their definitions first.

You can replace the default stdlib with --overwrite-stdpath <path>, where <path> can point to either a single .rizz file or a stdlib directory. You can also prepend extra files or directories with repeated -I <path> flags.

Multiple input files are compiled left-to-right after that implicit stdlib and any -I includes. Later files can refer to earlier files, but the reverse order is not supported yet.

Running from VS Code

Open any .rizz file and click the ▶ Run button in the editor title bar, or run the command Rizzo: Run Current File from the Command Palette.

The extension will:

1. Save the file
2. Compile it with rizzoc (auto-detected from local build or opam exec -- dune exec rizzoc --)
3. Compile the generated output.c with gcc (or the C compiler set in rizzoLsp.compiler.cc)
4. Run the resulting binary – all in an integrated terminal

Configuration (settings.json):

Setting	Default	Description
rizzoLsp.compiler.command	(auto)	Path to rizzoc binary. Leave empty to auto-detect.
rizzoLsp.compiler.cc	gcc	C compiler command (gcc or clang).

LSP and VS Code extension

To run the LSP server, use the command:

• LSP server: opam exec -- dune exec rizzolsp

VS Code extension development

The VS Code extension is located in the vscode-rizzo-lsp folder. It can easily be installed with

cd vscode-rizzo-lsp && npm install && cd ..
npm run ext:install

This installs the dependencies, builds the project and then installs the extension locally.

To compile the bundle with no VSIX: npm run compile

Debugging the extension

For development you might want to run the extension in a debug session, which allows you to set breakpoints and inspect variables in the LSP server code. To do this, you can run the debug configuration Run Rizzo Extension (repo root) from the repository root. This will launch a new VS Code window with the extension loaded. You can then open any .rizz file to see diagnostics, symbols, definitions, hover information, and completion suggestions provided by the LSP server.

• Run debug config: Run Rizzo Extension (repo root).
• Then open any .rizz file to get diagnostics, symbols, definition, hover, and completions (Ctrl+Space and typing-triggered suggestions).

Notes

• The extension contributes language configuration through package.json, so *.rizz files are automatically recognized.
• For true "just open folder and it works" without running a debug session, run the task rizzo: install local extension once (requires code CLI in PATH), then reopen VS Code.
• The C runtime headers (src/runtime/*.h) are bundled into the VSIX automatically by the vscode:prepublish step via npm run copy:runtime.

LSP Commands

The extension provides several commands accessible via the Command Palette (Ctrl+Shift+P):

Command	Description
Rizzo: Run Current File	Compile and run the active .rizz file
Rizzo: Check LSP Health	Show LSP server status and configuration
Rizzo: Restart LSP Server	Restart the language server

A status bar item shows the current LSP state (starting/running/stopped).

Testing

Run the test suite with:

npm run test
# or
opam exec -- dune test

Tests cover parsing, type checking, transformations, and the language service.

Documentation

• Thesis document: See pdf/ for the LaTeX thesis document
• Development notes: See notes/ for design decisions and progress
• Syntax reference: See notes/syntax.md for language syntax overview