C++ Lex using CSharp is a system software ( Lexical Analyzer) project where the input program is broken down into many fragments called tokens. Basically lexical analysis involves scanning the program to be compiled and recognizing the tokens that make up the source statements. Scanners are usually designed to recognize keywords, operators, and identifiers, as well as integers, floating point numbers, character strings, and other similar items that are written as part of source program. The exact set of tokens to be recognized depends upon the programming language being compiled and the grammar being used to describe it. Identifiers such as identifiers and integers are usually recognized directly as single tokens. The main aim of the project is to develop a lexical analyzer for C++ using Microsoft Visual CSharp 2008. The project aims at developing a lexical analyzer that identifies the keywords, identifiers, literals and comments as well.

The Lexical Analyzer will accept C++ program (code) as input and outputs the symbol table, literal table etc after tokenizing the input. A lexical analyzer is capable of doing the following.

¢ Remove all white space.
¢ Break the program into different tokens.
¢ Categorize each fragment as identifier, literal or a keyword.
¢ Display comment if there are any.
¢ Display the tokens in their corresponding tables.

I have used the concept of Collections in order to store the tokens. Collections Supports Linked Lists, Stacks and Hash table which has been used to the full extent. First every word or symbol in the input program are separated from each other and put into a node as and when the white space is encountered. Then these symbols are categorized into keywords, identifiers or literals. Comments are also taken into consideration. That is both single line and multi line comments are considered. After the symbols are categorized, these symbols are put in their respective tables. Four tables are used for literals, identifiers, keywords occurred and for list of keywords considered. A GUI concept is used to display the tables and their contents. Keywords are displayed along with the number of occurrences. Thus the project C++ Lex Using CSharp does the job of breaking the input program into fragments for any given C++ program