Spell checker using events composition

This first example is a Windows application that integrates the previously implemented spell checker (from Chapter 9, Functional Programming Techniques for Better State Management) using Rx, and explores how this can be leveraged to suggest alternatives and corrections. Consider the following code snippet:

    static void Main() 
    { 
        ObservableEventsDemo(); 
    }  

Initialize your input from here, with some basic controls that we will need, that is, a text box (used for keyword search) and a list box that provides suggestions/corrections for a given keyword. Take a look at the following code snippet:

    static void ObservableEventsDemo()
    {  
       // Input form

      var txtBoxSpellCorrect = new TextBox(); 
      var lstBoxSuggestions = new ListBox {
        Top = txtBoxSpellCorrect.Height + 10 }; 
      var frmSpellChecker = new Form { Controls = { txtBoxSpellCorrect,
        lstBoxSuggestions } }; 

Now, we will need to create...