Data commit

Task/Take-notes-on-the-command-line/F-Sharp/take-notes-on-the-command-line.fs

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+open System;;
+open System.IO;;
+
+let file_path = "notes.txt";;
+
+let show_notes () =
+    try
+        printfn "%s" <| File.ReadAllText(file_path)
+    with
+        _ -> printfn "Take some notes first!";;
+
+let take_note (note : string) =
+    let now = DateTime.Now.ToString() in
+    let note = sprintf "%s\n\t%s" now note in
+    use file_stream = File.AppendText file_path in (* 'use' closes file_stream automatically when control leaves the scope *)
+        file_stream.WriteLine note;;
+
+[<EntryPoint>]
+let main args =
+    match Array.length args with
+        | 0 -> show_notes()
+        | _ -> take_note <| String.concat " " args;
+    0;;