我该如何消除Haskell守卫中的解析错误？

问题描述

我正在尝试使用haskell代码来查找某人的bmi，为此我正在使用Guards

pls guide me fort his code
bmiTell :: (RealFloat a) => a -> String
bmiTell bmi
| bmi <= 18.5 = " You're underweight!"
| bmi <= 25.0 = "You're supposedly normal!"
| bmi <= 30.0 = "You're fat!"
| otherwise = “Something wrong!"

执行后，它给了我一个输入'|'的解析错误” 请给我一些替代方法

解决方法

缩进在Haskell中很重要。您必须缩进警卫。

bmiTell :: (RealFloat a) => a -> String
bmiTell bmi
  | bmi <= 18.5 = " You're underweight!"
  | bmi <= 25.0 = "You're supposedly normal!"
  | bmi <= 30.0 = "You're fat!"
  | otherwise = “Something wrong!"