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  • Wangqiang Li thinks this is interesting:

which is why we use (h w) here

From

Cover of Learn You a Haskell for Great Good!

Note

Maybe and List 作为context, 从中得到里面的值 可以直观的知道用 值构造匹配,
那 Function 呢? 那就是执行这个 Function 得到 以 Function为Context的值!