A TypeScript to Crystal compiler. All the beauty and power of TypeScript, with the speed and portability of Crystal.

// examples/async-await/src/test.ts

async function myAsyncFunction(): Promise<string> {
  return "Hello!";
}

async function main(): Promise<void> {
  myAsyncFunction() // you can also use await here of course
    .then(res => console.log(res));
}

main();

# examples/async-await/dist/test.cr

private def myAsyncFunction : MiniFuture(String)
  async! do
    return "Hello!"
  end
end
private def main : MiniFuture(Nil)
  async! do
    myAsyncFunction.then do |res|
      puts(res)
    end
    return
  end
end
await main

• All of the below instructions are temporary.
• You must have Crystal and TypeScript installed to be able to actually use it.

1. Clone the repository
2. Run npm i && tsc
3. Run npm start <directory> to compile all TypeScript files inside of <directory> OR npm start to compile all TypeScript files inside your current working directory

• cli:
  • watch mode
• codegen:
  • ignore advanced type generics (T extends, ternary operator, initializers) because Crystal doesn't support them
  • destructuring (this is so much harder than it needs to be, thanks TypeScript devs)
  • for..in (is this even necessary?)
  • macro the rest of the console library (warn, error, info, clear, etc.)
  • macro the ?? operator (a != nil ? a : b)
  • emit comments
  • disallow:
    • call expressions on arrow functions directly
    • type parameters in function types
• polyfills:
  • String (😭)
  • Object
  • Promise
• test:
  • StringBuilder class
  • commonly used utility functions
  • if statements with else/elsif branches