Use these 3 classes to add on the requirementsLexer.class

Shank.class ( The Main Class )

In this assignment, we will work toward completing our lexer. We will start by switching from just "WORD" to actual keywords. We will add the punctuation that we need. We will process string and character literals ("hello" ' a '), deal with/ignore comments and finally, we will deal with indentation levels. As you know, there are a lot of words in Shank that we must deal with. When we read (in English), we recognize words from the words that we have learned in the past. You might say that we associate a word with a concept or an idea. This association is a powerful concept and Java has support for it with HashMap. A HashMap is a data structure that maps (in the mathematical sense) or associates two values. It can also be called a "key-value store". In the Hash Map, you can provide a key and get a value. This is perfect for looking up words. We want to, lookup a string ("while" for example) and get a token type (tokenType.WHILE). HashMap knownWords = new HashMap>(i krownWords.put ("while", tokentype, WHILE); boolean doWeHaveWhile = knownWords.containskey ( "while"): tokenType whileTyee = knownWords.get ( "while" i Details Look through the Language Description and build a list of keywords. Add a HashMap to your Lexer class and initialize all the keywords. Change your lexer so that it checks each string before making the WORD token and creates a token of the appropriate type if the work is a key word. When the exact type of a token is known (like "WHILE"), you should NOT fill in the value string, the type is enough. For tokens with no exact type (like "hello"), we still need to fill in the token's string. Finally, rename "WORD" to "IDENTIFIER". Similarly, look through the Language Description for the list of punctuation. A hash map is not necessary or helpful for these - they need to be added to your state machine. Be particularly careful about the multi-character operators like := or >=. These require a little more complexity in your state machine. See the comment state machine example for an idea on how to implement this. Strings and characters will require some additions to your state machine. Create "STRINGLITERAL" and "CHARACTERLITERAL" token types. These cannot cross line boundaries. Note that we aren't going to build in escaping like Java does ( "This is a double quotel" that is inside a string" or ). Comments, too, require a bit more complexity in your state machine. When a comment starts, you need to accept and ignore everything until the closing comment character. Assume that comments cannot be nested {{ this is invalid } and will be a syntax error later\}. Remember, though, that comments can span lines, unlike numbers or words or symbols; no token should be output for comments. A state machine example: Your lexer should throw an exception if it encounters a character that it doesn't expect outside of a comment, string literal or character literal. Create a new exception type that includes a good error message and the token that failed. Ensure that the ToString method prints nicely. An example of this might be: ThislsAnldentifier 123!{