如何在Haskell中連接兩個列表

Question

我有兩個列表x = ["a","b","c"]和y = ["Argentina","Brazil","Canada"]。我想要一個列表，如[["a","Argentina"],["b","Brazil"],["c","Canada"]]。 任何人都可以幫我嗎？謝謝。

Answer 1

我不確定是否有更簡單的方法，但可以使用zip生成元組列表，然後使用map返回列表列表。

Prelude> map (\(a,b) -> [a,b]) $ zip ["a","b","c"] ["Argentina","Brazil","Canada"] 
[["a","Argentina"],["b","Brazil"],["c","Canada"]] 

編輯：丹尼爾·馬丁指出，zipWith更簡單。

Prelude> zipWith (\a b -> [a,b]) ["a","b","c"] ["Argentina","Brazil","Canada"] 
[["a","Argentina"],["b","Brazil"],["c","Canada"]] 

Answer 2

只需使用

zipWith (\x y -> [x,y]) 

Answer 3

沒有看到您的使用情況下，我猜想，元組其實就足夠了，而且更類型安全的，因此，這只是zip

x = ["a","b","c"] 
y = ["Argentina","Brazil","Canada"] 
z = zip x y 

Prelude> z 
[("a","Argentina"),("b","Brazil"),("c","Canada")]