PLC Project

Overview

This project is an implementation of a lexical analyzer (lexer) and parser for a programming language. It converts an input source code into a sequence of tokens and constructs an Abstract Syntax Tree (AST) for further processing.

Files

Lexer

• Lexer.java – Tokenizes an input character stream based on predefined lexical rules.
• LexException.java – Defines exceptions for lexical errors.
• Token.java – Represents individual tokens identified by the lexer.

Parser

• Parser.java – Parses the tokenized input into an AST following syntactic rules.
• Ast.java – Defines the AST structure, including expressions and statements.

Features

• Lexical Analysis: Identifies identifiers, numbers, strings, operators, and comments.
• Parsing: Constructs an AST from a sequence of tokens.
• Error Handling: Throws appropriate exceptions for invalid syntax or lexical errors.

Usage

1. Lexing

   Lexer lexer = new Lexer("let x = 5;");
   List<Token> tokens = lexer.lex();

2. Parsing

   Parser parser = new Parser(tokens);
   Ast.Source ast = parser.parseSource();

Dependencies

• Guava (for checkState assertions)
• Java SE 11+

Future Improvements

• Support for additional language constructs.
• Error reporting with line numbers.
• Improved AST visualization tools.