Typo in section "Functions" paragraph "Functions should only be one level of abstraction"

[AdmiralReality]

Hi!

I've spotted typo in section "Functions" paragraph "Functions should only be one level of abstraction" in point "Good". It's saying:

class BetterJSAlternative
{
    private string _tokenizer;
    private string _lexer;
    // ...

But both _tokenizer and _lexer are supposed to be classes Tokenizer and Lexer respectively. So it should be something like:

class BetterJSAlternative
{
    private Tokenizer _tokenizer;
    private Lexer _lexer;
    // ...