Haskell hello world赢得';不编译
这个代码有什么问题?试着做一个基本的哈斯克尔你好世界Haskell hello world赢得';不编译,haskell,Haskell,这个代码有什么问题?试着做一个基本的哈斯克尔你好世界 module Main ( hello ) where hello :: [Char] -> [Char] hello p = "Hello " ++ p ++ "!" main = let msg = hello "World" putStrLn msg 您缺少一个do: main = do let msg = hello "World" putStrLn msg 您还需要导出main: module Main
module Main
( hello )
where
hello :: [Char] -> [Char]
hello p = "Hello " ++ p ++ "!"
main =
let msg = hello "World"
putStrLn msg
您缺少一个
do
:
main = do
let msg = hello "World"
putStrLn msg
您还需要导出main
:
module Main ( main ) where
main = let msg = hello "World" in putStrLn msg
由于这是主模块,因此无需导出
hello
您在中缺少一个:
module Main ( main ) where
main = let msg = hello "World" in putStrLn msg
或者,没有do:main=putStrLn(hello“World”)
或main=putStrLn$hello“World”
或main=(putStrLn.hello)“World”或main=putStrLn。你好$“世界”