Question

I have a text file with the following structure:

KEYWORD0 DataKey01-DataValue01 DataKey02-DataValue02 ... DataKey0N-DataValue0N

KEYWORD1 DataKey11-DataValue11 DataKey12-DataValue12 DataKey13-DataValue13
_________DataKey14-DataValue14 DataKey1N-DataValue1N (1)

// It is significant that the additional datakeys are on a new line


(1) the underline is not part of the data. I used it to align the data.

Question: How do I use a regex to convert my data to this format?

<KEYWORD0>
    <DataKey00>DataValue00</DataKey00>
    <DataKey01>DataValue01</DataKey01>
    <DataKey02>DataValue02</DataKey02>
    <DataKey0N>DataValue0N</DataKey0N>
</KEYWORD0>
<KEYWORD1>
    <DataKey10>DataValue10</DataKey10>
    <DataKey11>DataValue11</DataKey11>
    <DataKey12>DataValue12</DataKey12>
    <DataKey13>DataValue12</DataKey13>
    <DataKey14>DataValue12</DataKey14>
    <DataKey1N>DataValue1N</DataKey1N>
</KEYWORD1>

Answer 1

Regex is for masochists, it’s a very simple text parser in VB.NET (converted from C# so check for bugs):

Public Class MyFileConverter
    Public Sub Parse(inputFilename As String, outputFilename As String)
        Using reader As New StreamReader(inputFilename)
            Using writer As New StreamWriter(outputFilename)
                Parse(reader, writer)
            End Using
        End Using
    End Sub

    Public Sub Parse(reader As TextReader, writer As TextWriter)
        Dim line As String
        Dim state As Integer = 0

        Dim xmlWriter As New XmlTextWriter(writer)
        xmlWriter.WriteStartDocument()
        xmlWriter.WriteStartElement("Keywords")
        ' Root element required for conformance
        While (InlineAssignHelper(line, reader.ReadLine())) IsNot Nothing
            If line.Length = 0 Then
                If state > 0 Then
                    xmlWriter.WriteEndElement()
                End If
                state = 0
                Continue While
            End If

            Dim parts As String() = line.Split(Function(c) [Char].IsWhiteSpace(c), StringSplitOptions.RemoveEmptyEntries)
            Dim index As Integer = 0

            If state = 0 Then
                state = 1
                xmlWriter.WriteStartElement(parts(System.Math.Max(System.Threading.Interlocked.Increment(index),index - 1)))
            End If

            While index < parts.Length
                Dim keyvalue As String() = parts(index).Split("-"C)
                xmlWriter.WriteStartElement(keyvalue(0))
                xmlWriter.WriteString(keyvalue(1))
                xmlWriter.WriteEndElement()
                index += 1
            End While
        End While

        If state > 0 Then
            xmlWriter.WriteEndElement()
        End If
        xmlWriter.WriteEndElement()
        xmlWriter.WriteEndDocument()
    End Sub
    Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, value As T) As T
        target = value
        Return value
    End Function
End Class

Note that I added a root element to the XML because .Net XML objects only like reading and writing conformant XML.

Also note that the code uses an extension I wrote for String.Split.