Syntax Analysis

Introduction:
Syntax analysis, also known as parsing, is the process of analyzing the source program to determine its structure according to the rules of a formal grammar. It involves breaking down the program into proper syntactic classes, such as statements, expressions, and identifiers. This analysis is crucial for subsequent stages of compilation or interpretation.

Lexical Analysis:
Lexical analysis is the first phase of the compilation process. It involves breaking the source program into a sequence of lexemes, which are the smallest meaningful units of the programming language. Lexemes include keywords, identifiers, operators, constants, and punctuation symbols. The lexical analyzer scans the source code character by character, grouping them into lexemes and associating them with token types. Token types represent different syntactic categories, such as keywords or identifiers.

Role of Lexical Analysis:
The main role of lexical analysis is to simplify the subsequent stages of compilation or interpretation. By dividing the source program into lexemes and token types, it provides a structured representation of the code, which is easier to process. This structured representation helps in identifying errors, generating meaningful error messages, and building the symbol table.

Syntax Analysis:
Syntax analysis follows lexical analysis and is the second phase of the compilation process. It takes the sequence of lexemes produced by the lexical analyzer and checks if it conforms to the rules of a formal grammar. The formal grammar defines the syntax of the programming language, including the order and structure of its components. The syntax analyzer constructs a parse tree, which represents the hierarchical structure of the program. This tree is then used for further processing, such as generating intermediate code or executing the program.

Role of Syntax Analysis:
The primary role of syntax analysis is to ensure that the source program is well-formed and conforms to the rules of the programming language. It detects and reports syntax errors, such as missing or misplaced punctuation, incorrect expression structure, or invalid use of keywords. Syntax analysis also provides a structured representation of the program, which can be used for subsequent stages, such as semantic analysis, optimization, and code generation.

Conclusion:
In conclusion, the action of parsing the source program into proper syntactic classes is known as lexical analysis. It breaks down the program into lexemes and token types, providing a structured representation of the code. Syntax analysis, on the other hand, checks if the sequence of lexemes conforms to the rules of a formal grammar and constructs a parse tree. Both lexical and syntax analysis are essential steps in the compilation or interpretation process, ensuring the correctness and meaningfulness of the source program.