wasm5: WebAssembly Virtual Machine in MoonBit

A WebAssembly virtual machine implementation in MoonBit.

Status

The virtual machine passes most WebAssembly specification tests with 11 individual tests skipped due to known limitations.

Supported Features

WebAssembly 1.0 Core:

• All basic instructions (arithmetic, logic, comparison, conversion)
• Memory operations (load, store, memory.grow, memory.size)
• Control flow (block, loop, if, br, br_if, br_table, call, call_indirect, return)
• Local and global variables
• Tables

Extension Proposals:

• Reference Types - funcref, externref, ref.null, ref.is_null, ref.func, typed function references
• Tail Call - return_call, return_call_indirect, return_call_ref
• Bulk Memory Operations - memory.copy, memory.fill, memory.init, data.drop
• Multi-value - Functions can return multiple values

Quick Start

# Run tests (requires wasm-tools to be installed)
moon run test --target native

# Run a WebAssembly module (invokes _start function)
moon run cmd/main -- run test/simple/print42.wasm