SmartFloat is a numerical data type library for sound floating-point computations in Scala. The library can perform sound computations with ranges of floating-point numbers and estimate the roundoff errors commited.

For example:

def cubeRoot = {
  val a: AffineFloat = 10
  var xn = AffineFloat(1.6)
  for(i <- 1 until 5) {
      xn = xn * ((xn*xn*xn + 2.0*a)/(2.0*xn*xn*xn + a))
  }
  println(xn.toStringWithAbsErrors)
  println(xn.interval)
}  

will compute the cube root of 10 by Halley's method and provide an upper bound on the absolute floating-point roundoff error committed on the final result:

2.1544 (1.3346e-15)
[2.1544346900318816,2.154434690031885]

You can download the source code and try it out. The only dependency is a small native library that you need to compile for your own platform, but for Linux and Mac this works without issues.

There is also a poster and a presentation available.

The library is mainly described in the following paper:

E. Darulova, V. Kuncak. Trustworthy Numerical Computation in Scala. OOPSLA 2011. PDF

The SmartFloat library is maintained by Eva Darulova.