turing-machine

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• turing-machine [[https://melpa.org/#/turing-machine][file:https://melpa.org/packages/turing-machine-badge.svg]] [[https://stable.melpa.org/#/turing-machine][file:https://stable.melpa.org/packages/turing-machine-badge.svg]] [[https://www.gnu.org/licenses/gpl-3.0.txt][file:https://img.shields.io/badge/license-GPL_3-green.svg]]

Implementation of a single tape turing machine simulator in emacs-lisp and python (separately).

Inspired by http://morphett.info/turing/turing.html

** Usage *** Syntax The syntax for turing code is described in the link above, but for redundancy: #+begin_quote Syntax:

• Each line should contain one tuple of the form ~ ~.
• You can use any number or word for ~~ and ~~, eg. ~10~, ~a~, ~state1~. State labels are case-sensitive.
• You can use any character for ~~ and ~~, or ~_~ to represent blank (space). Symbols are case-sensitive.
• ~~ should be ~l~, ~r~ or ~*~, denoting 'move left', 'move right' or 'do not move', respectively.
• Anything after a ~;~ is a comment and is ignored.
• The machine halts when it reaches any state starting with ~halt~, eg. ~halt~, ~halt-accept~.

Also:

• ~*~ can be used as a wildcard in ~~ or ~~ to match any character or state.
• ~*~ can be used in ~~ or ~~ to mean 'no change'.
• ~!~ can be used at the end of a line to set a breakpoint, eg ~1 a b r 2 !~. The machine will automatically pause after executing this line.
• You can specify the starting position for the head using ~*~ in the initial input. #+end_quote The [[./examples]] directory should contain relevant examples. Source should be listed near the top when not my own. *** Python Write a file with the syntax above, and pass it to the script as indicated below. This is in Python 3. It should be pretty trivial to implement in python 2. #+begin_example Usage: turing_machine.py FILENAME INITIAL turing_machine.py FILENAME INITIAL [-r|--rate] [RATE]

Options: -h --help -r --rate specify delay rate #+end_example *** Emacs

• Write a file/buffer with the syntax described above, and run ~turing-machine-execute~ to run the simulator.
• Add ~-- mode: turing-machine --~ to the top of the file to automatically start in ~turing-machine-mode~ when you next open the file.
• In ~turing-machine-mode~ you can press ~C-c C-c~ (~turing-machine-execute~) to start the machine.
• Within the code file, you can use ~;; INITIAL: [Some initial state]~ to denote the initial state and ~;; RATE: [some number]~ to denote the update rate in seconds.
  • If intial state is not set, you will be prompted for it through the minibuffer. To be prompted anyway, call ~turing-machine-execute~ with a prefix argument ~C-u~.
  • If rate is not set, it will default to the fastest speed (this is still pretty slow). With a double prefix argument ~C-u C-u~, you will be prompted for rate through the minibuffer
• Spaces are allowed in initial input, but surrounding spaces are trimmed. You can be explicit with ~_~.
• You can choose to hide visualization of spaces with an underscore by setting ~turing-machine-visual-spaces~ to ~nil~. ** Emacs Installation This package is on Melpa. To install using [[https://github.com/jwiegley/use-package][use-package]]: #+begin_src emacs-lisp (use-package turing-machine :ensure t) #+end_src

Using [[https://github.com/quelpa/quelpa-use-package][quelpa-use-package]]: #+begin_src emacs-lisp (use-package turing-machine :quelpa (turing-machine :fetcher github :repo "therockmandolinist/turing-machine")) #+end_src

Or [[https://github.com/quelpa/quelpa][quelpa]]: #+begin_src emacs-lisp (quelpa '(hacker-typer :fetcher github :repo "therockmandolinist/turing-machine")) #+end_src

Otherwise, download the files to somewhere on your load path, and enable turing-machine: #+begin_src emacs-lisp (require 'turing-machine) #+end_src

** Todo

• Better syntax highlighting.
• Get rid of cursor in ~turing-machine~ buffer.
• File extension