我不明白this--++和:haskell之间的区别是什么?
Prelude> "hi"++"there"
"hithere"
Prelude> "hi":"there"
<interactive>:12:6:
Couldn't match expected type `[Char]' with actual type `Char'
Expected type: [[Char]]
Actual type: [Char]
In the second argument of `(:)', namely `"there"'
In the expression: "hi" : "there"
Prelude>
为什么不说,还回 “hithere”?
谢谢你给我介绍':t'! – Micah 2012-07-19 21:49:33
@Micah:尝试':help' – 2012-07-19 22:13:00
@Micah:其他真正有用的是':info',它可以给你很多关于类型的信息。 – 2012-07-19 22:13:24