Lexical and Syntactic Analysis System

Overview

This project implements a Lexical Analyzer and Parser for analyzing and interpreting a programming language that includes Arabic keywords. It provides:

1. Tokenization (Lexical Analysis): Breaking the input source code into meaningful components (tokens).
2. Parsing (Syntactic Analysis): Building an Abstract Syntax Tree (AST) to represent the syntactic structure of the source code.

---

Components

1. TokenType (Enumeration)

Defines the different types of tokens that can be identified during lexical analysis:

• Identifiers: Ident
• Numeric Constants: Number
• Operators: AddOp, MulOp, LogOp, relOp
• Punctuation: OpenPar, ClosePar, OpenBrace, CloseBrace, OpenBracket, CloseBracket, Simecolon, Comma
• Reserved Words: Arabic keywords like اذا, اخر, بينما, ارجع, حقيقي, صحيح, خالى
• Equality Operators: equal_
• Invalid Tokens: invalid

2. Lexeme (Record)

Represents a token identified during lexical analysis:

• Properties:
  • value: The string value of the token.
  • type: The TokenType of the token.
  • line: The line number where the token appears.
  • column: The starting column number of the token.

3. Lexer Methods

• scan(string input): Analyzes input string to identify tokens.
• isNumber(string input): Checks if a string represents a valid number.
• isReal(string input): Checks for real numbers.
• isInt(string input): Checks for integers.
• isIdent(string input): Validates identifiers using a pattern.
• ResWord(string input): Identifies reserved words and maps them to TokenType.

4. Interfaces

IParser Interface

Defines methods for parsing syntactic constructs:

• parse(): Initiates the parsing process.
• DeclarationList, Declaration, VarDeclaration: Handle variable declarations.
• FunDeclaration: Handles function declarations.
• CompoundStmt, StatementList, Statement: Parse statements.
• Expression, SimpleExpression, AdditiveExpression, Term: Handle expressions.
• Call, Args: Parse function calls and arguments.

IParserServices Interface

Provides auxiliary methods for parsing:

• TypeSpecifier: Checks if a lexeme represents a type.
• addOp, mulOp, relOp: Check if a lexeme represents operators.
• CreateNode: Creates AST nodes.

5. Classes

Node Class

Represents a node in the AST:

• Properties:
  • left: Leftmost character position.
  • right: Rightmost character position.
  • Type: Syntactic construct type.
  • Children: List of child nodes.

Result Class

Encapsulates the result of parsing:

• Properties:
  • last: Position of the last successfully parsed character.
  • error: Error message if parsing failed.
  • node: AST node resulting from parsing.

---

Features

• Arabic Keywords: Supports tokens and reserved words in Arabic (e.g., اذا, اخر).
• Lexical Analysis: Accurately identifies tokens using regular expressions.
• Syntactic Parsing: Constructs an AST for the input source code.
• Extensibility: Modular design allows easy extension for new tokens and syntactic constructs.

---

Getting Started

Prerequisites

• .NET Core SDK
• A code editor like Visual Studio Code