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F# equivalent of VB.Net member initialization
initializepublicprivatestreamreader

I'm trying to initialize a type member in a similar way I do in VB.Net. The member requires a streamreader, but I only want the read to happen once. For this I would assign the private member to nothing and then check if it is nothing in the getter. Here is the equivalent code

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    Private Sub ExtractSource()

        mSourceText = ""
        Dim file = "FileToRead.txt"
        Dim sr As StreamReader
        If System.IO.File.Exists(file) Then
            Try
                sr = New StreamReader(file)
                mSourceText = sr.ReadToEnd
                sr.Close()
            Catch ex As Exception
            End Try
        End If
    End Sub

    Private mSourceText = Nothing
    Public ReadOnly Property SourceText() As ArrayList
        Get
            If mSourceText Is Nothing Then ExtractSource()
            Return mSourceText
        End Get
    End Property
.

This should be equivalent to your VB code:

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    let mutable mSourceText = None

    let extractSource() =
        mSourceText <- Some ""
        if System.IO.File.Exists file then
            try
                use sr = new StreamReader(file)
                mSourceText <- Some (sr.ReadToEnd())
            with _ -> ()

    member this.SourceText =
        match mSourceText with
        | None -> extractSource()
        | Some t -> t
By on 6/13/2017 12:45 AM ()

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