Ideas on how to extend Scalaxy/Compilets to support untyped trees for much more power and flexibility.

Scalaxy Compilets Parser Phase.scala

replace(
  {
    // $vparamss($x) are special variables that capture all parameter groups.
    // $vparams($x) would only capture one group
    @extend($type) def $someMethod($vparamss: $) = $body
  },
  {
    implicit class $someMethod(self: $type) extends AnyRef { 
      def $someMethod($vparamss: $) = $body 
      // $fresh$x is a special variable that picks a fresh name with fresh("x")
      def $fresh$f = {
        println("Infinite loop!")
        $fresh$f
      }
    }
  }
)

replace(
  {
    def $algo($list: List[$r]): $r = {
      $list match {
        case $h :: $rest =>
          $f($h) :: $algo($rest)
        case Nil => 
          Nil
      }
      $OR$
      if ($list.isEmpty)
        Nil
      else 
        $f($list.head) :: $algo($list.tail)
    }
  },
  {
    def $algo($list: List[$r]): $r = {
      var $fresh$l = $list
      var $fresh$b = collection.mutable.ListBuilder[$r]()
      while ($fresh$l ne Nil) {
        $fresh$b += $f($fresh$l.head)
        $fresh$l = $fresh$l.tail
      }
      $fresh$b.result()
    }
  }
)