Tic-Tac-Toe Game in Vim9script

A classic Tic-Tac-Toe game with AI opponents of varying difficulty. You play as X against the computer playing as O. Written in Vim9script to showcase game AI, board logic, and state management.

Features

• Multiple AI Difficulties: Play against Easy, Medium, or Hard opponents
• Score Tracking: Tracks wins, losses, and draws across games
• Alternating First Move: First player alternates between human and computer each round
• Popup Window UI: Clean, centered game interface
• Difficulty Cycling: Toggle AI difficulty between rounds
• Modern Vim9script: Demonstrates minimax algorithm and game logic

Requirements

• Vim 9.0 or later with Vim9script support
• NOT compatible with Neovim (requires Vim9-specific features)

Installation

Using Git

Unix/Linux/macOS:

git clone https://github.com/yegappan/tic-tac-toe.git ~/.vim/pack/downloads/opt/tic-tac-toe

Windows (cmd.exe):

git clone https://github.com/yegappan/tic-tac-toe.git %USERPROFILE%\vimfiles\pack\downloads\opt\tic-tac-toe

Using a ZIP file

Unix/Linux/macOS:

mkdir -p ~/.vim/pack/downloads/opt/

Download the ZIP file from GitHub and extract it into the directory above. Rename the extracted folder (usually tic-tac-toe-main) to tic-tac-toe so the final path matches:

~/.vim/pack/downloads/opt/tic-tac-toe/
├── plugin/
├── autoload/
└── doc/

Windows (cmd.exe):

if not exist "%USERPROFILE%\vimfiles\pack\downloads\opt" mkdir "%USERPROFILE%\vimfiles\pack\downloads\opt"

Download the ZIP file from GitHub and extract it into the directory above. Rename the extracted folder (usually tic-tac-toe-main) to tic-tac-toe so the final path matches:

%USERPROFILE%\vimfiles\pack\downloads\opt\tic-tac-toe\
├── plugin/
├── autoload/
└── doc/

Finalizing Setup

Since the plugin is in the opt directory, add this to your .vimrc (Unix) or _vimrc (Windows):

packadd tic-tac-toe

Then restart Vim and run:

:helptags ALL

Plugin Manager Installation

If using vim-plug, add to your config:

Plug 'path/to/tic-tac-toe'

Then run :PlugInstall and :helptags ALL.

For other plugin managers, follow their standard procedure for local plugins.

Usage

Starting the Game

:TicTacToe

Controls

Key	Action
h / ←	Move cursor left
j / ↓	Move cursor down
k / ↑	Move cursor up
l / →	Move cursor right
Enter or Space	Place your mark (X)
r	Reset and start new round
d	Cycle AI difficulty (Easy → Medium → Hard)
c	Clear score
q or Esc	Quit game

Game Rules

• 3×3 Grid: Standard Tic-Tac-Toe board
• Players: You are X, computer is O
• Turns: Alternate placing marks on empty cells
• Winning: Get three marks in a row (horizontal, vertical, or diagonal)
• Drawing: All cells filled with no winner
• First Move: Alternates between player and computer each round

Configuration

Set in your vimrc:

let g:tictactoe_difficulty = "medium"  " Options: "easy", "medium", "hard"

Game Difficulty

• Easy: Computer makes random valid moves
• Medium: Computer blocks obvious threats and takes opportunities
• Hard: Computer uses minimax algorithm for optimal play

Scoring

The game tracks:

• X (Your wins)
• O (Computer wins)
• D (Draws)

Press c to clear all scores and start fresh.

Vim9 Language Features Demonstrated

• Game AI: Minimax algorithm implementation for intelligent computer moves
• State Management: Board state representation and game logic
• Type Checking: Full type annotations throughout
• Classes: Board and game state management with encapsulation
• Modular Design: Separation between AI logic, UI, and game rules
• Popup Windows: Modern Vim UI with floating game window
• Game Loop: Turn-based game execution with input handling

License

This plugin is licensed under the MIT License. See the LICENSE file in the repository for details.