AnkitV15/LR-0-Parser

An LR(0) parser implementation in python. This repository includes the source code, documentation and examples for building and understanding LR(0) parsers.

LR(0) Parser

This repository contains a Python implementation of an LR(0) parser. The LR(0) parser is a type of bottom-up parser for analyzing context-free grammars used in compilers and interpreters.

Features

• Computes the closure of a production
• Handles state transitions with the goto function
• Generates parsing tables for terminals and non-terminals
• Parses and validates input strings

Installation

Prerequisites

• Python 3.6 or higher (3.9.12 recommended)
• termtables library for displaying parsing tables
• collections library for counting occurences

Steps

1. Clone the repository:

   git clone https://github.com/yourusername/LR0-parser.git
   cd LR0-parser

2. Install required packages:

   pip install termtables
   pip install collections

Usage

1. Run the script:

   python lr0_parser.py

2. Enter productions: You will be prompted to enter grammar productions one by one. Type end when you are done.

   

3. View augmented grammar and states: The script will display the augmented grammar and the generated states.

   

4. Parsing table: The parsing table will be displayed.

   

5. Enter the string to be parsed:

   Enter the string to be parsed: aabb
   

6. Parsing result: The script will display whether the string is parsable and provide the parsing table.