gistfile1.groovy

//Improve the guess using Newton's method
def improve = { guess, x ->
  (guess + x / guess) / 2
}

//Check if our guess is good enough, within a chosen threshold
def isGoodEnough = {guess, x ->
  abs(guess * guess - x) < 0.001
}

//iterate over guesses until our guess is good enough
def sqrtIter = { guess, x ->
  if (isGoodEnough(guess, x)) guess
  else sqrtIter(improve(guess, x), x)
}
  
//wrap everythin in the square root function call
def sqrt = {x -> srqtIter(1.0, x)}