在scala中对行进行递归计算 [英] recursive calculation over lines in scala

问题描述

我在输入中列出了以下字符串:

I Have the following list of stings in input:

val input = List(
"17 SD1-MONT_FF_13 7(14)",
"17 QXRI1-SEDDS_13 S(01)",
"17 XFDRI1-MONDT_TT_14 7(18)",
"17 SQXI1-SSENS_14 S(01)",
"12 CRI1-MSONT_TT_15 7(18)",
"13 QSDRI1-SEDNS_15 S(01)",
"14 WSQSRI1-DEVSISE S(05)")

我对以下函数进行了编码，该函数计算列表的每一行的第三个元素上的数据类型:

I coded the following function which calclulates the datatype over the third element of each line of the list :

但是我不知道如何在每一行上递归调用此函数，因此它将数据类型添加为每一行的第4个元素，预期结果应为如下列表:

But I don't know how to call this function recursively over each line so it adds the datatype as a 4th element is each line , the expected result should be a list as follows :

val input = List(
"17 SD1-MONT_FF_13 7(14) IntegerType",
"17 QXRI1-SEDDS_13 S(01) StringType",
"17 XFDRI1-MONDT_TT_14 7(18) IntegerType",
"17 SQXI1-SSENS_14 S(01) StringType",
"12 CRI1-MSONT_TT_15 7(18) IntegerType ",
"13 QSDRI1-SEDNS_15 S(01) StringType",
"14 WSQSRI1-DEVSISE S(05) StringType")

The function related to data type calculation is: 

def dataType (input:String) : String = (input.charAt(0), 

input.contains('F')) match {
  case ('S', _)  => "StringType"
  case ('7', false) => "IntegerType"
  case ('7', true) => "FloatType"
  case _ => "UnknowType"
}

推荐答案

所有您需要的是将确切的字符串值传递给dataType函数，如下所示

All you need is pass the exact string value to the dataType function as below

input.map(line => line +" "+ dataType(line.split(" ")(2)))

应该给您

17 SD1-MONT_FF_13 7(14) IntegerType
17 QXRI1-SEDDS_13 S(01) StringType
17 XFDRI1-MONDT_TT_14 7(18) IntegerType
17 SQXI1-SSENS_14 S(01) StringType
12 CRI1-MSONT_TT_15 7(18) IntegerType
13 QSDRI1-SEDNS_15 S(01) StringType
14 WSQSRI1-DEVSISE S(05) StringType

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