Alan

<p align=center> <img src="https://raw.githubusercontent.com/kelvindecosta/alan/master/assets/readme/logo.png" height="200px"/> <br> <span>A programming language for <em>designing</em> Turing machines.</span> <br> <a target="_blank" href="https://www.python.org/downloads/" title="Python version"><img src="https://img.shields.io/badge/python-%3E=_3.6-green.svg"></a> <a target="_blank" href="LICENSE" title="License: MIT"><img src="https://img.shields.io/badge/License-MIT-blue.svg"></a> <a target="_blank" href="https://pypi.python.org/pypi/alan/"><img alt="pypi package" src="https://badge.fury.io/py/alan.svg"></a> </p> <p align="center"> <a href="#walkthrough">Walkthrough</a> &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp; <a href="#installation">Installation</a> &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp; <a href="https://github.com/kelvindecosta/alan/wiki">Wiki</a> &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp; <a href="#citation">Citation</a> </p>

Installation

pip install alan

Walkthrough

This section describes a workflow.

For an in-depth guide navigate to the Wiki. Here are some useful links:

• Definition
• Syntax
• Interface

Consider the following example, the definition for a Turing machine that accepts all binary strings that are palindromic:

# This is a definition of a Turing Machine that accepts binary strings that are palindromes
' '
A*
    'X' 'X' < A
    'Y' 'Y' < A
    '0' 'X' > B
    '1' 'Y' > F
    ' ' ' ' > G
B                   # Starting with 0
    '0' '0' > B
    '1' '1' > B
    ' ' ' ' < C
    'X' 'X' < C
    'Y' 'Y' < C
F                   # Starting with 1
    '0' '0' > F
    '1' '1' > F
    ' ' ' ' < E
    'X' 'X' < E
    'Y' 'Y' < E
C
    '0' 'X' < D
    'X' 'X' < D
E
    '1' 'Y' < D
    'Y' 'Y' < D
D
    '0' '0' < D
    '1' '1' < D
    ' ' ' ' > A
    'X' 'X' > A
    'Y' 'Y' > A
G.
    'X' '0' > G
    'Y' '1' > G

Graph the machine:

alan graph examples/binary-palindrome.aln -f assets/readme/binary-palindrome.png

<p align="center"><img src="https://raw.githubusercontent.com/kelvindecosta/alan/master/assets/readme/binary-palindrome.png"></p>

Run the machine on some inputs:

• alan run examples/binary-palindrome.aln 101
  

  Accepted
  Initial Tape : 101
  Final Tape   : 10
  

• alan run examples/binary-palindrome.aln 1010
  

  Rejected
  Initial Tape : 1010
  Final Tape   : Y010
  

Animate the computation on some inputs:

• alan run examples/binary-palindrome.aln 101 -a -f assets/readme/binary-palindrome-accepted.gif
  

  

• alan run examples/binary-palindrome.aln 1010 -a -f assets/readme/binary-palindrome-rejected.gif
  

  

Citation

If you use this implementation in your work, please cite the following:

@misc{decosta2019alan,
    author = {Kelvin DeCosta},
    title = {Alan},
    year = {2019},
    howpublished = {\url{https://github.com/kelvindecosta/alan}},
}