scalaz/scalaz — pull request #179 by S11001001 (2012-11-07 22:02:22+00:00)
Title: Derived left/right biases for Bifoldable and Bitraverse.

```scala
scala> Bitraverse[\/].rightTraverse.traverse(42.left[Int])(x => Vector(x + 3))
res11: scala.collection.immutable.Vector[scalaz.\/[Int,Int]] = Vector(-\/(42))

scala> Bitraverse[\/].leftTraverse.traverse(42.left[Int])(x => Vector(x + 3))
res12: scala.collection.immutable.Vector[scalaz.\/[Int,Int]] = Vector(-\/(45))

scala> Bifoldable[\/].leftFoldable.foldMap(42.left[Int])(identity)
res14: Int = 42

scala> Bifoldable[\/].rightFoldable.foldMap(42.left[Int])(identity)
res15: Int = 0
```