Elixir - Quoted expressions

metaprogramming_1.exs

# Quote an expression (turn it into an AST)
foobar = quote do
  _ * _ = 42
end

IO.inspect(foobar)

# Define the function to be used when traversing the AST
answers = [2, 21]
put_awnsers = fn
  {:_, _meta, _args}, [head|tail] -> IO.inspect(head); {head, tail}
  node, acc -> IO.inspect(node); {node, acc}
end

IO.puts "---"

{generated_ast, acc} = Macro.prewalk(foobar, answers, put_awnsers)

IO.puts "---"

IO.inspect(generated_ast)
IO.puts "---"
IO.inspect(acc)

IO.puts "---"

{result, _bindings} = Code.eval_quoted(generated_ast)

IO.inspect(result)