pmwhite

[<CompiledName("Scan")>]
let scan<'T,'State> f (z:'State) (source : seq<'T>) = 
    checkNonNull "source" source
    let f = OptimizedClosures.FSharpFunc<_,_,_>.Adapt(f)
    seq { let zref = ref z
          yield !zref
          use ie = source.GetEnumerator() 
          while ie.MoveNext() do
              zref := f.Invoke(!zref, ie.Current)
              yield !zref }

pmwhite

using System;
using Windows.System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Input;

class KeyWatchTextBox : TextBox
{
    public event EventHandler WatchKeyPressed;