Class: XO::Engine

Inherits:
StateDesignPattern::StateMachine
  • Object
show all
Defined in:
lib/xo/engine.rb

Overview

The Engine encapsulates the game logic for Tic-tac-toe.

It is controlled by 4 actions:

  • start

  • stop

  • play

  • continue_playing

Each action may or may not change the state of the engine. This is important because it is the state of the engine that determines when the above actions can be called.

The engine can be in 1 of 3 states:

The engine begins life in the Init state.

Here’s a table showing which actions can be called in a given state:

State    | Actions
----------------------------------
Init     | start
Playing  | play, stop
GameOver | continue_playing, stop

Each action is defined in their respective state class.

Instance Method Summary collapse

Instance Method Details

#evaluator ⇒ Object 



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# File 'lib/xo/engine.rb', line 50

def evaluator
  Evaluator.instance
end

#initial_context ⇒ Object 



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# File 'lib/xo/engine.rb', line 46

def initial_context
  GameContext.new(:nobody, Grid.new)
end

#start_state ⇒ Object 



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# File 'lib/xo/engine.rb', line 42

def start_state
  Init
end