問計一類的實物斯卡拉VS哈斯克爾

Question

當詢問在Haskell的那種[Int]和[]我得到：

Prelude> :k [Int] 
[Int] :: * 
Prelude> :k [] 
[] :: * -> * 

這是有道理的：第一個是正確的類型，第二個是更高的親屬型。

但是，當我做同樣的斯卡拉：

scala> :k -v List[Int] 
scala.collection.immutable.List's kind is F[+A] 
* -(+)-> * 
This is a type constructor: a 1st-order-kinded type. 

scala> :k -v List 
scala.collection.immutable.List's kind is F[+A] 
* -(+)-> * 
This is a type constructor: a 1st-order-kinded type. 

...它說都是高kinded類型。爲什麼第一個沒有被歸類爲合適的類型？這種差異的原因是什麼？

Answer 1

似乎scala看到了List[Int]的[Int]部分非常清楚，但選擇忽略它，總是看「外部」型故意。

如果這是不正確的，那麼type ListOfInt = List[Int]其次:k -v ListOfInt將產生*不* -> *但事實並非如此：

scala> :k -v List 
scala.collection.immutable.List's kind is F[+A] 
* -(+)-> * 
This is a type constructor: a 1st-order-kinded type. 

scala> :k -v List[Int] 
scala.collection.immutable.List's kind is F[+A] 
* -(+)-> * 
This is a type constructor: a 1st-order-kinded type. 

scala> type ListOfInt = List[Int] 
defined type alias ListOfInt 

scala> :k -v ListOfInt 
scala.collection.immutable.List's kind is F[+A] 
* -(+)-> * 
This is a type constructor: a 1st-order-kinded type.