Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
627 views
in Technique[技术] by (71.8m points)

mapping - Haskell: how to map a tuple?

In Haskell, I can easily map a list:

map (x -> 2*x) [1,2]

gives me [2,4]. Is there any "mapTuple" function which would work like that?

mapTuple (x -> 2*x) (1,2)

with the result being (2,4).

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Here's a rather short point-free solution:

import Control.Monad (join)
import Control.Arrow ((***))

mapTuple = join (***)

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...