import org.stairwaybook.layout._

object Main extends App {

  val f = new ExprFormatter

  val e1 = BinOp("*", BinOp("/", Number(1), Number(2)), BinOp("+", Var("x"), Number(1)))
  val e2 = BinOp("+", BinOp("/", Var("x"), Number(2)), BinOp("/", Number(1.5), Var("x")))
  val e3 = BinOp("/", e1, e2)
  val e4 = UnOp("-", BinOp("+", Number(1), Number(2)))

  def show(e: Expr) = println(f.format(e) + "\n\n")

  for (e <- Array(e4, e1, e2, e3)) show(e)
}