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问题描述
在Scala中,我有一个像这样的正则表达式模式匹配: val Regex =(\d {4})/(\d {2})/(\d {2})。r val正则表达式(年,月,日)=2013/01/06
结果是:
year:String = 2013 month:String = 01 day:String = 06我如何在Haskell中实现类似的结果?换句话说,我可以匹配一个包含组的正则表达式并将组分配给标识符吗?
解决方案这适用于我:
Prelude Text.Regex.Posix> 2013/01/06=〜([0-9] +)/([0-9] *)/([0-9] *)::(String,String,String,[String]) (,2013/01/06,,[2013,01,06])(OS X上为ghci 7.4.2)
In Scala, I have a regular expression pattern match like this:
val Regex = """(\d{4})/(\d{2})/(\d{2})""".r val Regex(year, month, day) = "2013/01/06"The result is:
year: String = 2013 month: String = 01 day: String = 06How can I accomplish a similar result in Haskell? In other words, can I match a regular expression containing groups and assign the groups to identifiers?
解决方案This works for me:
Prelude Text.Regex.Posix> "2013/01/06" =~ "([0-9]+)/([0-9]*)/([0-9]*)" :: (String,String,String,[String]) ("","2013/01/06","",["2013","01","06"])(ghci 7.4.2 on OS X)
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模式匹配Haskell中的正则表达式模式
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