WARNING: EXPERIMENTAL FORK

This is an experimental fork of AssemblyScript maintained by btc-vision. It includes features that are not yet available in the official AssemblyScript release:

Experimental Features

• Closures - Full closure support with captured variables
• Try-Catch-Finally - Exception handling with try-catch-finally blocks
• Binaryen 125 - Updated to the latest Binaryen version (125.0.0)
• Enhanced Shadow Stack - Improved shadow stack pass for better GC integration

Changes from Upstream

1. Closure Support

   • Closure capture analysis and recompilation logic

2. Exception Handling

   • Try-catch-finally statement support
   • Enforced Error type in throw statements

3. Binaryen Upgrade (123 → 125)

   • Updated ExpressionId enum values to match Binaryen 125
   • Fixed shadow stack pass timing to handle lazy function compilation
   • Moved compileVisitGlobals/compileVisitMembers after shadow stack pass
   • Added iterative shadow stack transformation for newly compiled functions

Installation

npm install @btc-vision/assemblyscript

Usage

This fork is a drop-in replacement for AssemblyScript. Simply replace your import:

{
  "dependencies": {
    "@btc-vision/assemblyscript": "^0.29.0"
  }
}

Or if migrating from official AssemblyScript:

npm uninstall assemblyscript
npm install @btc-vision/assemblyscript

The CLI commands remain the same:

npx asc your-file.ts --outFile output.wasm

Original README

Development instructions

A development environment can be set up by cloning the repository:

git clone https://github.com/btc-vision/assemblyscript.git
cd assemblyscript
npm install
npm link

The link step is optional and makes the development instance available globally. The full process is documented as part of the repository:

• Compiler instructions
• Runtime instructions
• Test instructions