How does one write the Pythagoras Theorem in Scala?

Question

The square of the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides.

This is Pythagoras\'s Theore

Answer 1

Some thoughts on Daniel's answer:

I've experimented to generalize Numeric to Real, which would be more appropriate for this function to provide the sqrt function. This would result in:

def pythagoras[T](a: T, b: T)(implicit n: Real[T]) = {
   import n.mkNumericOps
   (a*a + b*b).sqrt
}

It is tricky, but possible, to use literal numbers in such generic functions.

def pythagoras[T](a: T, b: T)(sqrt: (T => T))(implicit n: Numeric[T]) = {
   import n.mkNumericOps
   implicit val fromInt = n.fromInt _

   //1 * sqrt(a*a + b*b)   Not Possible!
   sqrt(a*a + b*b) * 1    // Possible
}

Type inference works better if the sqrt is passed in a second parameter list.

Parameters a and b would be passed as Objects, but @specialized could fix this. Unfortuantely there will still be some overhead in the math operations.

You can almost do without the import of mkNumericOps. I got frustratringly close!