Programming-Language Lexer (Streamlit) A tiny compiler-design sandbox that lets you see how a lexer chops up source code.
Powered by Python Lex-Yacc (PLY) on the backend and Streamlit on the frontend.

What it does Multi-language tokenisation** – Handles Python, C/C++, and Java snippets. Detailed token output – Shows keywords, identifiers, literals, operators, braces, etc. Instant feedback – Paste code in the browser, hit Analyse, and watch the tokens appear.

Repo layout

File	Purpose
lang.py	Streamlit UI (text box + token table)
la.py	PLY lexer rules – add/modify regexes here
requirements.txt	App dependencies
runtime.txt	Pins Python 3.11 for smooth install on Streamlit Cloud

All token definitions live in la.py. Add new regex functions or tweak existing ones to support more languages or constructs. Changes hot-reload when you restart the Streamlit app.

The app is already hosted on Streamlit Community Cloud: https://compilerdesign.streamlit.app