Improved Complex Number in Groovy

Thank you for last comment in the previous blog. Here's the improved version of Complex Number.

Number.metaClass.plus = { n ->
  if(n instanceof Imaginary) {
    new Complex(r:delegate, i:n.v)
  }
}
Number.metaClass.getI = { ->
  new Imaginary(v: delegate)
}

class Complex {
  def r
  def i
  String toString() {
    "$r + ${i}i"
  }
}
class Imaginary {
  def v
  def plus(n) {
    if(n instanceof Number) new Complex(r:n, i:this.v)
  }
}

def b = 2 + 2.4.i
def c = 4.2.i + 2
println b
println b.class
println c
println c.class