我想从列表中删除一个项目,但它又回来了。
main = do
let y = ["aa","bb","cc","dd","ee","ff"]
let n = length y
replicateM_ (n-1) (deleteWord y)
deleteWord y = do
putStrLn "Write a word: "
word <- getLine
let new_y = delete word y
print new_y
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输出:
*Main> main
Write a word:
aa
["bb","cc","dd","ee","ff"]
Write a word:
bb
["aa","cc","dd","ee","ff"]
Write a word:
cc
["aa","bb","dd","ee","ff"]
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我希望 和"aa"保持"bb"删除状态,并且不再回到列表中。