How to convert a Haskell Traversable into a Vector?

Question

If I have a Traversable instance, xs, how do I convert it into a Vector?

Answer 1

All Traversable instances are also Foldable, so you can write something like

toVector :: Foldable t => t a -> Vector a
toVector = Vector.fromList . Foldable.toList
{-# INLINE toVector #-}

This might make an intermediate list though, if that doesn't get fused away. The inlining should help make fusion more likely.