Lexical Parser

Python project providing a lexical analyzer and recursive-descent parser for a custom grammar. This repository contains the backend code used by a simple web UI for visualizing tokens and parse trees.

Features

• Tokenizer / lexer
• Recursive descent parser
• Web frontend (Flask) serving static HTML/CSS/JS to interact with the parser
• Utilities for error handling and visualization

Repository Structure

• app.py - Flask application entrypoint
• config.py - Application configuration
• lexer/ - Tokenizer and token type definitions
• parser/ - Grammar, recursive descent parser, and parse tree utilities
• templates/ - Jinja2 HTML templates for the web UI
• static/ - CSS and JS for the front end
• utils/ - Helper utilities (errors, visualizer)
• requirements.txt - Python dependencies
• text_analyzer.py - (Top-level script, likely for CLI/testing)

Quick Start

Prerequisites

• Python 3.10+ recommended
• pip

1. First, clone the repo & change the directory

cd PLCDModule/lexical-analyzer/

2. Create a virtual environment

python -m venv venv
source venv/bin/activate  # Mac/Linux

OR

venv\Scripts\activate     # Windows

3. Install dependencies

pip install -r requirements.txt

4. Run the application

python app.py

OR

export FLASK_APP=app.py
export FLASK_ENV=development
flask run

5. Open browser & Navigate to http://localhost:3000

Tests

There are no automated tests included in this repo currently. Adding unit tests for the tokenizer and parser is highly recommended.