https://github.com/cs-astronaut/regex-to-automata
A Tool for Drawing the DFA/NFA of a Regex for a Regular Language
https://github.com/cs-astronaut/regex-to-automata
automata-theory dfa dfa-minimization finite-automata formal-languages nfa nfa-to-dfa-conversion powerset-construction regex-to-automata regular-expression thompson-construction
Last synced: 4 months ago
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A Tool for Drawing the DFA/NFA of a Regex for a Regular Language
- Host: GitHub
- URL: https://github.com/cs-astronaut/regex-to-automata
- Owner: CS-Astronaut
- License: mit
- Created: 2025-05-05T02:50:59.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-05-29T00:59:58.000Z (about 1 year ago)
- Last Synced: 2025-09-16T03:01:48.270Z (9 months ago)
- Topics: automata-theory, dfa, dfa-minimization, finite-automata, formal-languages, nfa, nfa-to-dfa-conversion, powerset-construction, regex-to-automata, regular-expression, thompson-construction
- Language: Python
- Homepage:
- Size: 534 KB
- Stars: 4
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Regular Expression to DFA Converter
This project implements a tool that converts regular expressions to Finite Automata (DFA & NFA) with visualization capabilities. It provides a step-by-step conversion process from regular expressions to NFA (Non-deterministic Finite Automaton) and then to DFA, including minimization of the resulting DFA.
## Features
- Regular expression parsing and AST construction
- Thompson's construction algorithm for converting regex to NFA
- Subset construction algorithm for converting NFA to DFA
- Hopcroft's algorithm for DFA minimization
- Visualization of both NFA and DFA using Graphviz
- Support for basic regular expression operators:
- Concatenation (implicit)
- Union (`U`)
- Kleene star (`*`)
- Parentheses for grouping
- Epsilon transitions (`ε`)
- Binary alphabet (`0` and `1`)
---
## Requirements
- Python 3.x
- Graphviz (for visualization)
## Installation
1. Clone the repository:
```bash
git clone https://github.com/CS-Astronaut/Regex-To-Automata
cd Regex-To-Automata
```
2. Install the required Python package:
```bash
pip install graphviz
```
---
## Usage
Run the program:
```bash
python main.py
```
When prompted, enter a regular expression using the following syntax:
- Use `U` for union (e.g., `0U1` for "0 or 1")
- Use `*` for Kleene star (e.g., `0*` for "zero or more 0s")
- Use `ε` for epsilon transitions
- Use parentheses for grouping (e.g., `(0U1)*`)
The program will generate two visualization files:
- `output_nfa.png`: Visual representation of the NFA
- `output_dfa.png`: Visual representation of the minimized DFA
## Example
Input regular expression: `(0U1)*`
This will generate:
1. An NFA using Thompson's construction
2. A DFA using subset construction
3. A minimized DFA using Hopcroft's algorithm
4. Visual representations of both the NFA and DFA
---
## Implementation Details
The project consists of several key components:
1. **Parser**: Converts regular expressions into an Abstract Syntax Tree (AST)
2. **Thompson Construction**: Converts AST to NFA
3. **Subset Construction**: Converts NFA to DFA
4. **Hopcroft Minimization**: Minimizes the DFA
5. **Visualization**: Generates visual representations using Graphviz
---
## ScreenShots
### Ex1
`(0U1)*(0(0U1)*0)(0U1)*` = Representing A Language That Contains The Strings With **At least two 0s**
*(0(0U1)*0)(0U1)*/output_dfa.png)
*(0(0U1)*0)(0U1)*/output_nfa.png)
### Ex2
`(0U1)*1011(0U1)*` = Representing A Language That Contains The Strings With **Substring of 1011**
*1011(0U1)*/output_dfa.png)
*1011(0U1)*/output_nfa.png)
### Ex3
`1*01*01*` = Representing A Language That Contains The Strings With **Exactly two 0s**
### Ex3 Union Ex2 !
*Also Can Draw The Machine That Accepts The Union Of Two Languages*
`(1*01*01*)U((0U1)*1011(0U1)*)` = Representing A Language That Contains The Strings With **Substring of 1011** or **Exactly two 0s**
U((0U1)*1011(0U1)*)/output_dfa.png)
U((0U1)*1011(0U1)*)/output_nfa.png)
---
## License
This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.