Lexical Analyser for Grouping Characters into Tokens

The process of breaking down a code into smaller meaningful components is known as lexical analysis. This process is performed by a tool called a lexical analyzer or scanner. The main task of a lexical analyzer is to group the input characters into meaningful sequences, which are called tokens. These tokens can then be used by the parser for further analysis.

Importance of Lexical Analysis

Lexical analysis is the first step in the compilation process. It is essential to perform lexical analysis before any other processing can be done. The output of the lexical analyzer is a sequence of tokens that are passed on to the parser. The parser then uses these tokens to build the parse tree, which is used for further analysis.

Working of Lexical Analyzer

The lexical analyzer reads the input code character by character. It groups the characters into tokens based on the rules defined by the programming language. For example, in the C programming language, the keyword "if" is a token, and the symbol "{" is also a token. The lexical analyzer identifies these tokens by matching the input characters with the predefined rules.

Once the tokens are identified, the lexical analyzer assigns a token type to each token. For example, the token "if" may be assigned a token type of "IF". Similarly, the symbol "{" may be assigned a token type of "LEFT_BRACE".

Conclusion

In conclusion, the lexical analyzer is used for grouping characters into tokens. It is an essential tool in the compilation process, and its output is used by the parser for further analysis. The lexical analyzer reads the input code character by character and groups the characters into tokens based on the rules defined by the programming language.