Foldable, Traversable, Monoid etc. are all far better abstractions than what Scala collections provide, and they don't lead to unmanageable inheritance hierarchies and ridiculous APIs. How many bugs have been caused by that? A few hundred maybe? Does Set equality work in the current release or is that broken again? Is it possible to do thread safe efficient merges in immutable collections yet?
The only thing Scala collections offers that Haskell doesn't is the CanBuildFrom travesty. At least in Clojure you can chain transformations together without generating tons of intermediate values. In Scala you're forced to choose between being ridiculously inefficient or using iterators.
(It seems like you've got interesting things to say, but you're being a bit strident. It bums me out that Scala discussions on HN take such a heated tone.)
In the rare cases where you actually need to convert between collection types, it's usually trivial and more efficient to do it manually. Essentially they've added tons of complexity for negligible benefit. One of my main gripes with the Scala collections library is that it's overly complex and that this complexity has been the source of hundreds of bugs.
If there was any real benefit to the way it's currently done they wouldn't be hiding the true type signature for things like `List.map` in the official Scaladocs.
Additionally, it seems that moving from lists to a different collection type still involves rewriting your whole code due to the insane idea of using different functions by default (fmap/map, mempty/[], mappend/++).
I just don't have to deal with any of these design mistakes in Scala. Having sane defaults and stuff that "just works" consistently are a huge benefit.
I can't even imagine what you are talking about, so I can't say if they "fixed it" or not.
>Additionally, it seems that moving from lists to a different collection type still involves rewriting your whole code due to the insane idea of using different functions by default
"I did something dumb and now I don't like it". So, don't do it? Why were you using map in the first place?
>I just don't have to deal with any of these design mistakes in Scala
I don't have to deal with them in haskell either. But I do have to deal with the hundreds of other mistakes scala made if I use it.