Expand rows, given count, using Seq.unfold

unfoldTest1

// usage: unfoldTest1 inFile outFile 

(*
expected input is below

some text once,1
some text twice,2
some text thrice,3

intended output:

some text once,1
some text twice,1
some text twice,1
some text thrice,1
some text thrice,1
some text thrice,1

*)

open System
open System.IO

// ========================================================
// define any constants, values, etc
// ========================================================



// ========================================================
// define all types, functions
// ========================================================

let createTupleWithCount (line:string) =
    let lineArray  = line.Split(',')
    let count = int32 lineArray.[1]
    lineArray.[1]        <- string 1
    let updatedLine = lineArray |> String.concat "," 
    // printfn "%A %d" updatedLine count     
    (updatedLine, count)

let expandRows (text:string, number:int32) =
    if number = 0 
    then None
    else
        let element = text                  // "element" will be in the generated sequence
        let nextState = (element, number-1) // threaded state replacing looping 
        Some (element, nextState)
           
// cleanup
let flushAndClose (strWriter : StreamWriter) =
    strWriter.Flush |> ignore
    strWriter.Close |> ignore

// ========================================================
// ** begin main **
// ========================================================
[<EntryPoint>]
let main argv =
    // TODO: robustify handling of command line args
    //       ensure correct # of arguments
    //       ensure input file exists

    if argv.Length <> 2 then
        printfn "%A" "Dude! I need an Inputfile, an Outputfile" 
        // setup ==========================================
        let inFile  = argv.[0]
        use outFile = new StreamWriter(argv.[1])
        // let barTarget = int32 argv.[2]

 
        File.ReadLines(inFile)                  
            |> Seq.map createTupleWithCount
            |> Seq.unfold expandRows
            |> Seq.iter outFile.WriteLine
        
        // cleanup ========================================
        flushAndClose outFile    
 
    0 // return an integer exit code 
// ========================================================
// ** end main ** 
// ========================================================