从功能上说，用分隔符分割字符串的最佳方法是什么? [英] What is the best way to split a string by a delimiter functionally?

问题描述

我试图用Haskell编写程序，该程序将使用以逗号分隔的一串整数，将其转换为整数列表，并将每个数字加1.

I tried to write the program in Haskell that will take a string of integer numbers delimitated by comma, convert it to list of integer numbers and increment each number by 1.

例如"1,2，-5，-23,15"->[2,3，-4，-22,16]

下面是生成的程序

import Data.List

main :: IO ()
main = do
  n <- return 1
  putStrLn . show . map (+1) . map toInt . splitByDelimiter delimiter
    $ getList n

getList :: Int -> String
getList n = foldr (++) [] . intersperse [delimiter] $ replicate n inputStr

delimiter = ','

inputStr = "1,2,-5,-23,15"

splitByDelimiter :: Char -> String -> [String]
splitByDelimiter _ "" = []
splitByDelimiter delimiter list =
  map (takeWhile (/= delimiter) . tail)
    (filter (isPrefixOf [delimiter])
       (tails
           (delimiter : list)))

toInt :: String -> Int
toInt = read

对我来说，最难的部分是对函数 splitByDelimiter 进行编程，该函数需要一个字符串并返回字符串列表

The most hard part for me was programming of function splitByDelimiter that take a String and return list of Strings

"1,2，-5，-23,15"->["1"，"2"，-5"，-23"，"15"]

考虑到它的工作原理，我对它的编写方式不满意.括号很多，所以看起来像Lisp.此外，该算法在某种程度上是人为的:

Thought it is working, I am not happy with the way it is written. There are a lot of parentheses, so it looks Lisp like. Also the algorithm is somewhat artificial:

1. 将分隔符添加到字符串，1,2，-5，-23,15"

生成所有尾巴的列表 [，1,2，-5，-23,15"，"1,2，-5，-23,15"，，2，-5，-23,15，....]

过滤并只保留以定界符 [，1,2，-5，-23,15"，，2，-5，-23,15"，...开头的字符串.]

Filter and left only strings that begins with delimiter [",1,2,-5,-23,15", ",2,-5,-23,15", .... ]

删除第一个定界符并采用符号，直到满足下一个定界符为止. ["1"，"2"，....]

Drop first delimiter and take symbols until next delimiter will be met ["1", "2", .... ]

所以问题是:

我如何改善功能 splitByDelimiter ?

我可以删除定界符的前缀和掉落并直接分割字符串吗?

Can I remove prepend and drop of delimiter and make direct split of string?

我该如何重写函数以减少括号?

How I can rewrite the function so there will be less parentheses?

可能我错过了一些东西，并且已经有了该功能的标准功能吗?

May be I miss something and there are already standard function with this functionality?

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