petal

A programming language that compiles to web assembly.

# Mix of TypeScript and Rust syntax
fn add(a: Int, b: Int): Int  {
  return a + b
}

let three = add(1, 2)

# Exposed functions are exposed to the host environment in the compiled wasm module
# This function can be called from JavaScript on the web
# The goal is to automatically generate a TypeScript API for the wasm module
expose fn do_work(n: Int): Int {
  return n * 2
}

todo

This is a rough list of everything that needs to be done

• Compiler structure setup
  • Errors
  • Lexer/Parser
  • IR generation
  • Type checking
  • Wat generation
  • Wasm bytes generation
• Testing architecture
  • Snapshot tests
  • Output comparison
  • Assertions
• Primitive constants
• Binary operations
• Unary operations
• Control flow
  • If
  • Loops
  • Return
• Functions
  • Creation
  • Calling
  • Return values
• Import host functions
• Encode wasm directly
• Memory
• Strings
• Modules
• Structs
• Arrays
• Generics
  • Generic typechecking
  • Polymorphic wasm generation
• Standard library
• Number casting
• VSCode syntax highlighting
• TypeScript bindings
• Match expressions
• Component spec generation
• Website
  • Landing page
  • Docs
  • Dev blog
  • Playground

examples

How do we know that the language is actually useful?

• Hello world
• Fibonacci
• FizzBuzz
• Wasm4 game
• Interop with TypeScript
• HTTP handler