#+title: Octans
#+subtitle: Octans is a program to solve Algot's Wordplay (Wordsearch) puzzles
#+export_file_name: index
#+setupfile: ~/.emacs.d/org-templates/projects.org

| Website         | https://andinus.nand.sh/octans             |
| Source          | https://git.tilde.institute/andinus/octans |
| GitHub (mirror) | https://github.com/andinus/octans          |

* Demo

This was recorded with ~asciinema~.

[[https://asciinema.org/a/385500][https://asciinema.org/a/385500.png]]

+ Octans v0.2.3: [[https://andinus.unfla.me/resources/projects/octans/v0.2.3_2022-01-12_sample_input.mp4][Visualized Output]]

+ Octans v0.1.0 - finds 10 solutions to a puzzle:
  https://asciinema.org/a/385598
+ Octans v0.1.0: https://asciinema.org/a/385500

+ Octans 2021-01-14: https://asciinema.org/a/384464
+ alt-link (download): https://andinus.nand.sh/static/octans

* Installation

Octans is released to CPAN, you can get it from there or install it from
source. In any case, ~zef~ is required to install the distribution.

You can run Octans without ~zef~. Just run ~raku -Ilib bin/octans~ from
within the source directory.

- *Note*: Octans requires ~WWW~ module. You can however chose to not install
  it if you wish to run it locally. Checkout the ~without-www~ branch.

** Release

1. Run ~zef install octans~.

Octans should be installed, try running ~octans --version~ to confirm.

** From Source

You can either download the release archive generated by cgit/GitHub or
clone the project if you have ~git~ installed.

*** Without ~git~

1. Download the release:
   - https://git.tilde.institute/andinus/octans
   - https://github.com/andinus/octans/releases
2. Extract the file.
3. Run ~zef install .~ in source directory.

*** With ~git~

All commits will be signed by my [[https://andinus.nand.sh/static/D9AE4AEEE1F1B3598E81D9DFB67D55D482A799FD.asc][PGP Key]].

#+begin_src sh
# Clone the project.
git clone https://git.tilde.institute/andinus/octans
cd octans

# Install octans.
zef install .
#+end_src

* Documentation

** Implementation

Initially it went over the list of words & checked if they exist in the
grid. This was very slow.

Currently it walks the grid & checks if the current string exist in the
dictionary. This is faster for these reasons:

- The dictionary is sorted, we perform binary range search on the
  dictionary to return the list of all words that start with specific
  string.
- Starting positions are limited.

If the dictionary wasn't sorted then this probably would've been slower
than previous implementation.

The ~neighbors~ subroutine (=lib/Octans/Neighbors.rakumod=) was taken from
my AoC (Advent of Code) 2020's day-11 solution.

** Options

*** dict

Octans's default dictionary file is =/usr/share/dict/words=, use ~--dict~
flag to change the dictionary. The words in dictionary must be seperated
by a newline (=\n=) & sorted alphabetically.

*** visualize

Generates a video solution for the puzzle.

*** length

Minimum word length to look for. Default is 7.

*** path

The path to be passed must be a *readable file* or an *url* in either
format:

- Link when you view it from your local instance:
  https://tilde.zone/web/statuses/105531207939242077

- Link from Algot's profile:
  https://mastodon.art/@Algot/105333136907848390

*** verbose

This will increase verbosity.

* News

** v0.2.3 - 2022-01-12

+ Add visualize option.

  ~--visualize~ now generates a video solution for the puzzle using Cairo
  and ffmpeg.

** v0.2.0 - 2021-03-04

+ Removed ~sample~ option

  ~--sample~ will not solve the sample puzzle.

+ Removed shorthand for verbose option

  ~-v~ won't work in ~v0.2.0~.

+ Change representation of visited squares

  When ~--verbose~ was passed, it would print the solved puzzle with
  visited squares replaced with fancy characters. Now it marks them by
  adding:

  - ~*~ to visited + gray squares (start positions)
  - ~/~ to visited squares

+ Removed time taken

  Time taken won't be printed anymore.

  #+begin_quote
  It was misleading because the time printed was not the time taken to
  find that specific word, it was the time taken to find all the words
  upto that word. It would reset for each starting position.
  #+end_quote

** v0.1.4 - 2021-02-19

+ Fixed the puzzle parsing regex

  The older regex fails to parse this puzzle:
  https://mastodon.art/@Algot/105690195742318751.

** v0.1.3 - 2021-01-24

+ Added an option to specify minimum word length.

** v0.1.2 - 2021-01-20

+ Input puzzle can now be of any size & not restricted to 4x4 grid.

** v0.1.1 - 2021-01-20

+ Read puzzle from a file.

** v0.1.0 - 2021-01-19

+ Improved performance by using a better algorithm to find words in the
  grid.