https://github.com/grkw/gratie

A Rust-based interpreter for Gratie, my esoteric programming language based on Piet
https://github.com/grkw/gratie

esolang rust

Last synced: 3 days ago
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A Rust-based interpreter for Gratie, my esoteric programming language based on Piet

• Host: GitHub
• URL: https://github.com/grkw/gratie
• Owner: grkw
• License: mit
• Created: 2024-11-19T22:36:32.000Z (3 months ago)
• Default Branch: master
• Last Pushed: 2025-01-28T22:02:03.000Z (15 days ago)
• Last Synced: 2025-01-28T23:19:35.451Z (15 days ago)
• Topics: esolang, rust
• Language: Rust
• Homepage:
• Size: 367 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
Gratie ("grah-tee")




  

    

  

  

  



My version of the [Piet programming language](https://dangermouse.net/esoteric/piet.html). Made in collaboration with Jordan during the first half of the W1'24 batch at the [Recurse Center](https://www.recurse.com/).

(Piet Mondrian was a *Dutch* artist. According to Google Translate, "gratie" is Dutch for "grace"!)

## Design

I designed Gratie to be a minimalist version of Piet while retaining its esoteric-ness. The main components of the interpreter are the parser (parses the text-based input program), grid (stores the parsed input as a grid of `Colors`), and stack (stores the values of the program). We put all the pieces together with the program execution logic in `interpreter.rs`.

## Usage

To write your own Gratie program:

1. Specify pixel colors in a comma-separated text file. These are the colors:



and this is the mapping from hue change steps to command:

| Hue change steps | Command       |

|------------------|---------------|

| 1                | add           |

| 2                | multiply      |

| 3                | pop           |

| 4                | in(char)      |

| 5                | out(number)   |

| 6                | duplicate     |

| 7                | out(char)     |

| 8                | in(number)    |

| 9                | push          |

| 10               | divide        |

| 11               | subtract      |

2. Run `cargo build && ./target/debug/gratie -d PATH/TO/YOUR_PROGRAM.txt` to run the repl. Currently, the available commands are `step` (execute one command) and `run` (run entire program and print result).

## Examples

Push 3 onto the stack



Print 7 to the console



## Acknowledgements

### Helpful resources on how Piet works

- [Visual video explanation of what's going on with the "direction pointer" and "codel chooser"](https://youtu.be/IcmCvT5whk0?si=cvZTspfWsUEzuZf1&t=402)

- [User-friendly in-browser Piet IDE done by a former Recurser](https://gabriellesc.github.io/piet/) and [another one](https://piet-editor.github.io/)

- [Examples for implementing control flow in Piet](https://web.archive.org/web/20190818054404/http://homepages.vub.ac.be/~diddesen/piet/index.html)

## License

Gratie is licensed under the MIT License Copyright (c) 2025.

See the LICENSE for information on the history of this software, terms & conditions for usage, and a DISCLAIMER OF ALL WARRANTIES.

All trademarks referenced herein are property of their respective holders.