This is what my CLexicalAnalyser class do. This token represents an identifier. An identifier is a sequence of characters that can represent variable names, class names, function names and so on. This token represents an integer. This token represents a real number.
Real number can start with a decimal point.
This token represents a string. This token represent an unrecognised token in the lexical analysis. Therefore this lexical analyser uses the former to define a new line. This token denotes that there are no more tokens. This class represent a token.