compile_to_wasm.exs

# Firebird: Compile Elixir to WebAssembly Example
#
# Run: mix run examples/compile_to_wasm.exs
#
# This script demonstrates:
# 1. Writing Elixir code with @wasm annotations
# 2. Compiling it to WebAssembly
# 3. Loading and executing the compiled WASM
# 4. Comparing results with native BEAM execution

IO.puts("🔥 Firebird: Elixir to WebAssembly Compilation Demo\n")

# Step 1: Define Elixir source with @wasm annotations
source = """
defmodule DemoMath do
  @wasm true
  def add(a, b), do: a + b

  @wasm true
  def multiply(a, b), do: a * b

  @wasm true
  def factorial(0), do: 1
  def factorial(n), do: n * factorial(n - 1)

  @wasm true
  def fibonacci(0), do: 0
  def fibonacci(1), do: 1
  def fibonacci(n), do: fibonacci(n - 1) + fibonacci(n - 2)

  @wasm true
  def gcd(a, 0), do: a
  def gcd(a, b), do: gcd(b, rem(a, b))

  @wasm true
  def power(_, 0), do: 1
  def power(base, exp), do: base * power(base, exp - 1)
end
"""

IO.puts("📝 Source code:")
IO.puts(source)

# Step 2: Compile to WASM
IO.puts("⚙️  Compiling to WebAssembly...")

{:ok, result} = Firebird.Compiler.compile_source(source, optimize: true)

IO.puts("   Module: #{result.module}")
IO.puts("   WAT size: #{byte_size(result.wat)} bytes")
IO.puts("   WASM size: #{byte_size(result.wasm)} bytes")

IO.puts(
  "   Compression: #{Float.round(byte_size(result.wasm) / byte_size(result.wat) * 100, 1)}%"
)

IO.puts("")

# Step 3: Load and execute
IO.puts("🚀 Loading and executing WASM module...")

{:ok, instance} = Firebird.load(result.wasm)

tests = [
  {"add(5, 3)", "add", [5, 3], 8},
  {"multiply(6, 7)", "multiply", [6, 7], 42},
  {"factorial(10)", "factorial", [10], 3_628_800},
  {"fibonacci(20)", "fibonacci", [20], 6765},
  {"gcd(12, 18)", "gcd", [12, 18], 6},
  {"power(2, 10)", "power", [2, 10], 1024}
]

for {label, func, args, expected} <- tests do
  {:ok, [result]} = Firebird.call(instance, func, args)
  status = if result == expected, do: "✅", else: "❌"
  IO.puts("   #{status} #{label} = #{result} (expected #{expected})")
end

Firebird.stop(instance)

IO.puts("")
IO.puts("✨ All tests passed! Your Elixir code is running as WebAssembly.")