Do You Gosu?

Early days yet but it looks interesting. It reminds me somewhat of C# circa .NET 3.5

• var
• closures (blocks, lambdas)
• enhancements (I think this is like extension methods)
• object initializers

var square = \ x : Number-> x * x 
  var indsquare = \ x: Number, y: Number ->
      print(java.lang.String.format("%3d %7.2f",
          {y.intValue(), square(x)}))

  var values = { 1, 2, 3, 5, 7, 11, 13, 17, 19, 23 }
  values.eachWithIndex(\val, index -> indsquare(val, index+1))

So, square and indsquare are blocks.

And we get this result:

1    1.00
  2    4.00
  3    9.00
  4   25.00
  5   49.00
  6  121.00
  7  169.00
  8  289.00
  9  361.00
 10  529.00

What is the type of values? java.util.ArrayList!
And we were able to call eachWithIndex on it and pass another block as a parameter.

One negative--the Eclipse plug-in requires a Ganymede install. It doesn't work with Helios.
Update: 11/12/2010
As Carson noted in the comments, there are instructions in the gosu-lang discussion forums that show how to make it work with Helios. I've tried it and it seems to work.