我第一次玩 GHCi,我在编写多行函数时遇到了一些麻烦。我的代码如下:
Prelude> :{
Prelude| let diffSquares lst = abs $ squareOfSums lst - sumOfSquares lst
Prelude| where
Prelude| squareOfSums lst = (fst (sumsAndSquares lst))^2
Prelude| sumOfSquares lst = snd (sumsAndSquares lst)
Prelude| sumsAndSquares = foldl (\(sms,sqrs) x -> (sms+x,sqrs+x^2)) (0,0)
Prelude| :}
它给出了以下错误:
<interactive>:1:142: parse error on input `='
有人可以指出我所缺少的方向吗?