gistfile1.fs

// I'm trying to translate C# code to F# for my training
// http://www.fincher.org/tips/Languages/csharp.shtml

open System
open System.IO

// A. Hello world program
let helloWorld = Console.WriteLine "Hello World!"

// C. Read and print an entire file
let readAll = // a.
    let contents = System.IO.File.ReadAllText @"C:\sample.txt"
    // Below is 3 ways of writing output
    // I don't know why but it requires type annotation for Console.WriteLine
    // (Console.WriteLine:string->unit) <| "contents = " + contents
    // "contents = " + contents |> Console.WriteLine
    Console.WriteLine("contents = " + contents)


let getFileAsString fileName = // b.
    let mutable streamReader : StreamReader = null
    let mutable contents = null
    try
        let fileStream = new FileStream(fileName,FileMode.Open, FileAccess.Read)
        streamReader <- new StreamReader(fileStream)
        contents <- streamReader.ReadToEnd()
    finally
        if streamReader <> null then streamReader.Close()
    contents

let readAllLines = // c.
    let lines = System.IO.File.ReadAllLines @"Sample.txt"
    Console.WriteLine("contents={0}",lines.Length)

let readAllByStream = // d.
    let sr = new StreamReader "Sample.txt"
    while not sr.EndOfStream do
        sr.ReadLine() |> Console.WriteLine

// D. Writing stuff
let writeAll = // a.
    let myText = "Line1" + Environment.NewLine + "Line2" + Environment.NewLine
    System.IO.File.WriteAllText(@"C:\sample2.txt",myText)

let writeAllByStream =
    let fileStream = new FileStream("C:\sample2.txt",FileMode.OpenOrCreate,FileAccess.Write)
    let streamWriter = new StreamWriter(fileStream)
    try streamWriter.WriteLine "Howdy World."
    finally if streamWriter<>null then streamWriter.Close()


let writeCreatedTime =
    for i in 0..5000 do
        using (File.CreateText(String.Format(@"C:\sandbox\sample{0}.txt",i)))
            (fun w->
                let msg=string DateTime.Now + "," + string i
                w.WriteLine msg
                Console.WriteLine msg
                )
    Console.ReadLine()