小编Ric*_*isi的帖子

例如,这是一个功能:

iffthen :: [String] -> Parser String
iffthen a = do 
x <- symbol (head a)
               y <- booleana (head (tail a))
               z <- symbol (head (tail (tail a)))
               k <- assignP (head (tail (tail (tail a))))
               l <- symbol (head (tail (tail (tail (tail a)))))
               m <- assignP (head (tail (tail (tail (tail (tail a))))))
               return k

我需要看看每个指令到底做了什么

例如,我在输入中有一个字符串:"aaa bbb ccc dddd",我的函数给了我

["aaa", "bbb", "ccc", "dddd"]

要么

("aaa", "bbb", "ccc", "dddd")

有可能吗？